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ENF Future PV Technologies Review

(3rd Edition)

2010-2011

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Authors: Stephen Temple, CTO, ENF Alice Tao, Industry Analyst Manager, ENF Editors: Bernhard Dimmler, CEO, Würth Elektronik Research Bill Rever, Strategy Manager, BP Solar Dr. Arnulf Jäger-Waldau, European Commission Joint Research Centre

Note: Information in this survey has largely come from public sources and its accuracy accepted in good faith. Any corrections of fact from any company mentioned in this survey should be sent to ENF, and all reasonable efforts will be made to inform customers of this report (for whom we have up-to-date e-mail addresses) of such corrections. Information from companies not mentioned in this survey or supplementary information from companies mentioned is also welcome and will be carefully considered for any future revision of the report.

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Main Index PV Future Technologies Review .................................................................................................................... 7 

Introduction to the 3rd Edition ....................................................................................................................... 7 Part I - Economic Effects Shaping Technology Directions ......................................................................... 8 

Section Index ................................................................................................................................................. 8 1. The Solar PV Market ................................................................................................................................. 8 

1.1 Who are the real customers? .............................................................................................................. 8 1.2 Solar powered “battery driven” products ............................................................................................. 9 1.3 Off grid solar powered applications .................................................................................................... 9 1.4 Off-grid electricity supply ..................................................................................................................... 9 1.5 Renewable generation of electricity for the electricity grids .............................................................. 10 1.6 Renewable micro-generation of electricity for the electricity grids .................................................... 11 1.7 Building Integrated PV (BIPV) Market .............................................................................................. 11 

2. Forces shaping the success/price of a PV technology ........................................................................... 12 2.1 Technological Advantage v Economies of Scale .............................................................................. 12 2.2 Strategy Rules for successfully getting new solar PV technologies to market ................................. 14 2.3 Funding Dynamics behind new technologies ................................................................................... 15 

3. The solar PV industry cost drive to grid parity ........................................................................................ 18 3.1 Cost of What? ................................................................................................................................... 18 3.2 Cost per Watt ($/Wp) of solar PV modules ....................................................................................... 18 3.3 Installed system cost ......................................................................................................................... 26 3.4 Levelized Cost of Electricity (LCOE) ................................................................................................. 28 

4. Drive for Higher Efficiency ....................................................................................................................... 29 5. Efficiency - from Lab to Field ................................................................................................................... 31 6. Do standard test conditions paint an accurate picture of “Efficiency”? ................................................... 32 7. Impact of “Game Playing” on a more competitive PV industry ............................................................... 37 

7.1 Manufacturers and Governments/Regulators ................................................................................... 37 7.2 Manufacturers and Suppliers ............................................................................................................ 38 7.3 Manufacturers and their Competitors ............................................................................................... 38 7.4 Manufactures and their Customers ................................................................................................... 39 

8. The Risks of the Business - (Chaos Theory) .......................................................................................... 40 8.1 Risks facing all industries .................................................................................................................. 40 8.2 Risks particular to the solar PV industry ........................................................................................... 41 8.3 Risks particular to a specific solar PV technology ............................................................................ 42 8.4 Risks specific to the particular commercial enterprise ...................................................................... 44 8.5 Risk Summary ................................................................................................................................... 45 

9. What is Characterising the Solar PV Industry today ............................................................................... 46 10. Forecasting Technology Progress over the next 5 Years ..................................................................... 47 

Part II - Review of Critical Materials ............................................................................................................. 49 Section Index ............................................................................................................................................... 49 1. General Introduction ................................................................................................................................ 49 2. Polysilicon ............................................................................................................................................... 51 

2.1 Introduction ....................................................................................................................................... 51 2.2 Established Silicon Refining Technologies for polysilicon ................................................................ 51 2.3 Emerging Scene of Silicon Refining Technologies for polysilicon .................................................... 55 2.4 Implications for the solar PV industry ............................................................................................... 60 2.5 Polysilicon Suppliers ......................................................................................................................... 61 

3. Indium ...................................................................................................................................................... 62 3.1 General Introduction ......................................................................................................................... 62 3.2 Forces that will determine the market price of indium ...................................................................... 62 3.3 Market Prices and Trends ................................................................................................................. 68 3.4 Indium Suppliers ............................................................................................................................... 70 

4. Tellurium .................................................................................................................................................. 71 4.1 General Introduction ......................................................................................................................... 71 4.2 Forces Determining the Price of tellurium ......................................................................................... 71 4.3 Market Prices and trends .................................................................................................................. 72 4.4 Tellurium Suppliers ........................................................................................................................... 73 

5. Gallium .................................................................................................................................................... 74 5.1 General Introduction ......................................................................................................................... 74 5.2 Forces determining the price of gallium ............................................................................................ 74 5.3 Market prices and trends .................................................................................................................. 75 

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5.4 Gallium Suppliers .............................................................................................................................. 75 6. Germanium .............................................................................................................................................. 76 

6.1 General Introduction ......................................................................................................................... 76 6.2 Forces determining the price of germanium ..................................................................................... 76 6.3 Market prices and trends .................................................................................................................. 77 6.4 Germanium Suppliers ....................................................................................................................... 78 

7. Molybdenum ............................................................................................................................................ 79 7.1 General introduction .......................................................................................................................... 79 7.2 Forces determining the price of molybdenum ................................................................................... 79 7.3 Market Prices and trends .................................................................................................................. 80 7.4 Molybdenum Suppliers ..................................................................................................................... 80 

8. Cadmium ................................................................................................................................................. 81 8.1 Cadmium Suppliers ........................................................................................................................... 81 

9. Pastes...................................................................................................................................................... 82 9.1 Metallization paste ............................................................................................................................ 82 9.2 Alternatives to Pastes ....................................................................................................................... 83 

10. Glass and Alternatives to Glass ............................................................................................................ 84 10.1 Glass ............................................................................................................................................... 84 10.2 Alternatives to Glass ....................................................................................................................... 84 10.3 Glass Suppliers ............................................................................................................................... 84 

11. Other Materials ...................................................................................................................................... 85 11.1 Backsheet ....................................................................................................................................... 85 11.2 Lamination encapsulent .................................................................................................................. 85 

Part III - Key machines used in the factory processes .............................................................................. 86 Section Index ............................................................................................................................................... 86 1. Introduction .............................................................................................................................................. 86 2. Semiconductor deposition technologies .................................................................................................. 87 

2.1 Liquid Phase Epitaxy (LPE) .............................................................................................................. 87 2.2 Chemical Vapour Deposition (CVD) ................................................................................................. 87 2.3 Molecular Beam Epitaxy ................................................................................................................... 92 2.4 Physical Vapour Deposition (PVD) ................................................................................................... 93 2.5 Laser Pyrolysis .................................................................................................................................. 95 

3. Diffusion Furnaces .................................................................................................................................. 96 3.1 List of Diffusion Furnace Suppliers ................................................................................................... 97 

4. “Printing” deposition technologies ........................................................................................................... 98 4.1 Introduction ....................................................................................................................................... 98 4.2 Screen Printing ................................................................................................................................. 98 4.3 Inkjet Printing .................................................................................................................................... 99 4.4 Spray Coating ................................................................................................................................. 101 4.5 Deposition of the PV active material ............................................................................................... 101 4.6 Focused Flow Extrusion (from PARC) ............................................................................................ 102 4.7 Light Induced Printing (Electroplating) ............................................................................................ 102 

5. Other Deposition Processes ................................................................................................................. 103 5.1 Chemical Bath Deposition ............................................................................................................... 103 5.2 Ultrasonic Direct Energy Plating ..................................................................................................... 103 5.3 Close Space Sublimation ................................................................................................................ 103 5.4 Vapour Transport Deposition .......................................................................................................... 104 

6. Semiconductor Wafer Cutting ............................................................................................................... 105 6.1 Saw Technology ............................................................................................................................. 105 6.2 Cleaving technology ........................................................................................................................ 106 6.3 Future Developments ...................................................................................................................... 106 6.4 List of Suppliers .............................................................................................................................. 107 

7. Laser Technology .................................................................................................................................. 108 Part IV - Factory Processes for PV Technologies .................................................................................... 111 

Section Index ............................................................................................................................................. 111 1. Introduction ............................................................................................................................................ 111 2. Silicon crystalline PV technologies ........................................................................................................ 112 

2.1 Monocrystalline Ingot production .................................................................................................... 112 2.2 Polycrystalline Ingot Production ...................................................................................................... 112 2.3 Cell production ................................................................................................................................ 113 2.4 Panel Production ............................................................................................................................. 116 

3. Thin Film Production Processes ........................................................................................................... 119 3.1 Production process for a-Si (amorphous silicon) solar PV cells ..................................................... 119 

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3.2 Production process for CIS/CIGS Technology solar PV cells ........................................................ 123 3.3 Production process for CdTe Technology solar PV cells ............................................................... 125 

Part V - Factual Survey of PV Technologies ............................................................................................. 128 Section Index ............................................................................................................................................. 128 Section Pre-amble:- Explanation of the organisation of this section ......................................................... 128 1. Monocrystalline Solar PV Technology .................................................................................................. 130 

1.1 “Benchmark” Sawn Wafer Technology ........................................................................................... 130 1.2 Thinner Silicon Wafer Technology .................................................................................................. 133 1.3 Edge Defined Film-fed Growth Process (EFG)............................................................................... 135 1.4 String Ribbon .................................................................................................................................. 137 1.5 Monocrystalline - Back-Contact SunPower Technology ................................................................. 140 1.6 Sanyo HIT Technology ................................................................................................................... 141 1.7 Suntech Pluto Technology (variant of the PERL technology) ......................................................... 143 1.8 n-Type Monocrystalline Silicon PV Cells ........................................................................................ 144 1.9 Monocrystalline - Silicon Sliver Cells .............................................................................................. 145 1.9 Spherical Solar Cell ........................................................................................................................ 147 

2. Multicrystalline - Benchmark Silicon Sawn Wafer Technology ............................................................. 150 2.1 Benchmark Silicon Sawn Wafer Technology .................................................................................. 150 2.2 Back-Contact EWT Technology ...................................................................................................... 152 2.3 Angle Buried Contact (ABC) Cell .................................................................................................... 154 2.4 Selective Emitter Cell ...................................................................................................................... 155 2.5 Light Capturing Ribbon ................................................................................................................... 157 

3. Thin Film ................................................................................................................................................ 160 3.1 a-Si Family (including single, tandem and triple junctions) ............................................................. 160 3.2 CIS Family of solar PV technology ................................................................................................. 169 3.3 Thin film - CdTe Family of solar PV Technology ............................................................................ 180 3.4 CTZSS (Copper (Cu), Tin (Sn), Zinc (Zn), Sulfur (S), and/or Selenium (Se)) ................................ 184 3.5 Crystalline Silicon on Glass (CSG) ................................................................................................. 185 3.6 FeS2 (Iron Pyrite) Solar PV Cell ..................................................................................................... 188 

4. Very High Performance PV Cells .......................................................................................................... 190 4.1 Single and Double junction (GaAs) ................................................................................................. 190 4.2 Multi-junction (GaAs) ...................................................................................................................... 191 4.3 Indium, Gallium, Nitrogen (Full Spectrum) ...................................................................................... 196 4.4 Gallium Nitride/silicon tandem solar cell. ........................................................................................ 197 

5. Third Generation ................................................................................................................................... 199 5.1 Dye Sensitised ................................................................................................................................ 199 5.2 Third Generation - Organic Polymer ............................................................................................... 206 5.3 Nano-technology (Quantum dots) ................................................................................................... 212 5.4 Multi-junction Nanowire PV Cells .................................................................................................... 220 5.5 List of Suppliers of Third Generation PV Technologies .................................................................. 221 

6. Concentrator PV Technology ................................................................................................................ 222 6.1 Low Concentration PV (LCPV) (Under 5 suns) .............................................................................. 223 6.2 High Concentration PV (HCPV) (Over 5 suns and typically 500 suns) .......................................... 228 6.3 Combined CPV Electricity and Direct Heating Systems ................................................................. 239 6.4 - List of CPV suppliers .................................................................................................................... 243 

Part VI Thermo PV Technology (TPV) ........................................................................................................ 244 Section Index ............................................................................................................................................. 244 1. Introduction ............................................................................................................................................ 244 2. PV Cell Technology ............................................................................................................................... 245 3. Filters ..................................................................................................................................................... 245 4. System Efficiency .................................................................................................................................. 245 5. Cell Efficiency ........................................................................................................................................ 245 6. Industrial Capacity ................................................................................................................................. 246 7. Future Research Directions .................................................................................................................. 247 

Part VII Innovative Solar PV Films, Cells, Panels & Designs .................................................................. 248 Section Index ............................................................................................................................................. 248 1. Transparent Solar Cells ......................................................................................................................... 248 2. Coloured Solar PV Modules .................................................................................................................. 251 3. Innovative Panel Designs (Roof Tiles and Shingles) ............................................................................ 253 4. Combined PV Flat Panel and Thermal Water Heating ......................................................................... 256 5. Building Integrated PV ........................................................................................................................... 259 6. Other Innovations .................................................................................................................................. 260 

6.1 Light Wavelength Conversion Films and Luminescent solar concentrators ................................... 260 

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6.2 Light Splitting PV Receiver ............................................................................................................. 261 6.3 Integrated solar power electronic circuits ....................................................................................... 262 6.4 Microscopic solar cells for attachment to fabrics ............................................................................ 262 6.5 Solar Roads .................................................................................................................................... 262 

7. Silexium SiC Anti-reflective coating solution ......................................................................................... 263 Part VIII - Solar PV Generated AC Energy ................................................................................................. 264 

Section Index ............................................................................................................................................. 264 Sections Pre-amble Introduction ............................................................................................................... 264 1. Inverters ................................................................................................................................................ 265 

1.1 The architecture of inverters to solar PV modules .......................................................................... 265 1.2 The Basic efficiency of Inverters ..................................................................................................... 266 1.3 List of Suppliers .............................................................................................................................. 267 

2. Charge Controllers ................................................................................................................................ 268 3. Mounts and Trackers ............................................................................................................................. 269 

3.1 Fixed Mounts .................................................................................................................................. 269 3.2 Single-Axis Trackers and Mounts ................................................................................................... 269 3.3 Two-axis Mounts ............................................................................................................................. 270 3.4 Tracker Drives ................................................................................................................................. 270 3.5 List of Suppliers .............................................................................................................................. 271 

4. Batteries ................................................................................................................................................ 272 4.1 The Lead Acid Battery Evolution .................................................................................................... 272 4.2 Other types of batteries currently in use ......................................................................................... 272 4.3 Future Developments in Battery Technology .................................................................................. 272 4.4 List of Suppliers .............................................................................................................................. 275 

5. Other Innovations .................................................................................................................................. 276 5.1 Solar Panel Automated Cleaning .................................................................................................... 276 5.2 Solar PV Farm Fault Monitoring ..................................................................................................... 276 

Part IX - The Solar Powered Products Revolution ................................................................................... 277 Section Index ............................................................................................................................................. 277 1. Solar Applications Product Market ........................................................................................................ 277 2. Markets .................................................................................................................................................. 278 3. Technology ............................................................................................................................................ 279 

3.1 Solar Cells Only .............................................................................................................................. 279 3.2 Solar Cells Plus Motor .................................................................................................................... 279 3.3 Solar Cells Plus Battery Plus Motor ................................................................................................ 280 3.4 Solar Cells Plus Battery Plus Lights ............................................................................................... 281 3.5 Solar Cells Plus Portable Electronic Device ................................................................................... 283 3.6 Solar Cells Plus Battery Plus Portable Electronic Device ............................................................... 283 3.7 Solar Cells Plus Battery Plus Static Electronic Device ................................................................... 283 

4. List of Suppliers ..................................................................................................................................... 284 5. Discussion and Conclusion ................................................................................................................... 285 

Part X - Quality and Reliability of Solar PV Systems ............................................................................... 286 Section Index ............................................................................................................................................. 286 1. The Solar PV Quality System ................................................................................................................ 286 2. Material Quality Control ......................................................................................................................... 287 3. Factory Testing ...................................................................................................................................... 288 4. Quality Standards and Certification by third party testers ..................................................................... 289 5. Feedback from the field ......................................................................................................................... 290 6. Research programmes to address particular issues ............................................................................. 292 

Part XI - Survey of Solar PV Research in University & Public/Private Research Laboratories ........... 293 Section Index ............................................................................................................................................. 293 1. Introduction ............................................................................................................................................ 293 2. ENF survey of solar PV research .......................................................................................................... 295 

America - North ..................................................................................................................................... 295 America South....................................................................................................................................... 312 Asia ....................................................................................................................................................... 313 Australasia ............................................................................................................................................ 327 Europe ................................................................................................................................................... 329 Middle-east and Africa .......................................................................................................................... 357 

Annex - ENF Classification of Research into Solar PV Technologies ................................................... 360 Part XII - Glossary of Terms used in the Solar PV Industry .................................................................... 361 

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The solar PV/battery combination competes directly mainly with wind power amongst the renewable energy offerings (depending upon local climate) and engine/generator sets in respect of fossil fuels. What runs off the electricity produced could be a wide variety of electrical items. A part of this market does depend upon government subvention for rural electrification in developing countries. The supply chain that provides off-grid solar PV power supplies for remote dwellings is relatively compact and is in fact largely the traditional solar PV industry prior to the arrival of “the feed-in tariff” and other incentives for PV owners. It remains a market with huge potential in some developing countries.

The characteristics of this sub-market affecting the choice of solar PV technology are:

• Presumption of reliability in the local climate

• Largest hours of electricity/$ The above three markets are expanding in absolute market size but shrinking rapidly in terms of market share due to the explosion of demand created by government backing of renewable energy technologies with cross subsidised feed-in tariffs, targeted tax breaks and grants. 1.5 Renewable generation of electricity for the electricity grids (within the climate change political agenda).

This is currently an “artificial” market created by governments discriminating against much cheaper traditional means of generating electricity by burning coal, gas and oil. It is an absolutely necessary discrimination in three important respects. First it is the price to be paid for reducing global carbon emissions. Second, it is the price to be paid for achieving a strategic goal of becoming less dependent on politically unstable countries for oil and gas suppliers and the attendant security costs. Third, most of the alternative energy technologies, like solar PV technology, need time and markets to advance the state of the art to where they can become competitive without subsidy. One might also add in savings of some off-balance sheet costs such as health, and other social costs of certain fossil fuels as well as noting important benefits for developing countries in respect of economic development and local employment from electricity arriving in areas that would otherwise have none. Since governments are mandating significant subsidies they are, at least in part, the customer. Many do influence the mix of non-carbon electricity generating sources eg solar PV, nuclear (or not) etc. In this way they determine the total size of market addressable by the solar PV industry. But few discriminate between particular solar PV technologies although there are beginning to be exceptions to this.

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following:

Figure 5 - International comparison of factory labour wage rates

In addition, in a separate report, they have estimated the labour rates in China for urban factories to be $1.47 (11.74 Yuan) per hour in 2006 (Source: Monthly Labor Review April 2009). This is even less than Mexico on the above table. What flows from these statistics is the importance of manufacturers in high wage economies automated the production of solar PV modules to the extent possible. The alternative strategy is off-shoring the manufacture to low wage economies. First Solar has a factory in Malaysia, QS Solar and Canadian Solar Inc have factories in China, and there are others but there has been relatively little off-shoring in the solar PV industry to to-date with both Germany and the USA, relatively high wage locations, having a substantial local manufacturing base and accompanying this has been substantial progress in factory automation. This situation could be changing as most PV manufacturers in developed countries are considering either establishing bases in low wage economies or beginning to outsource production to companies already operating in those economies.

3.2.4 Energy Costs Some solar PV technologies require high temperature processes that are energy intensive for example the refinement of polysilicon. The manufacture of solar cells can also involve high temperature processes such as diffusion of boron over the silicon wafers. Thus energy costs are a not insignificant cost in the manufacture of solar PV cells and particularly for the first generation silicon technologies (mono and multi crystalline silicon PV cells). Energy costs vary from country to country and in large countries such as the US and China the costs can vary within the country. Below is some data from the International Energy Agency on the cost of electricity taken from their 2009 report and show a wide variation in price. The IEA data does not include China so we have taken the estimate given by one of our industry expert editors:

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The biggest commercial pressure is on improving the efficiency of a-Si technology as there is market resistance to a-Si solar PV modules for the roof-top market, which is area limited, and the lower efficiency is a barrier to sales (despite efforts by suppliers to show that a-Si can perform better in Northern climes than multi-crystalline silicon). There is a view by some solar PV companies that a-Si technology will need to surpass a stabilised module efficiency of 12% to really shift market perceptions for the roof top market.

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8. The Risks of the Business - (Chaos Theory) “Chaos theory” was an idea coming out of IBM research laboratory to describe a process that had so many complex forces determining the outcome that to all intents and purposes the relationship between the inputs and the outcome is “chaotic” and therefore unpredictable. The most exhaustive guide for the unpredictable forces that could impact the solar PV industry can be found in the US SEC filing from publicly listed solar PV companies. They are carefully drafted texts to serve a legal rather than informative function. They set out every imaginable risk in no particular order and with no commentary on how they might arise. They say everything but by not differentiating the risks, they convey very little. We believe that the risks that have been identified deserve much closer inspection and at least qualitative analysis to see how they might actually impact the progress of a solar PV technology on the basis of what we know today. We have taken three such filings (SunPower, Evergreen Solar and DayStar) and extracted the list of risk factors they have identified in their businesses. We have broken these into four distinct categories of risk:

Risks facing all industries Risks particular to the solar PV industry Risks particular to a specific solar PV technology Risks specific to the particular commercial enterprise

We group to risk factors under the above headings and select the briefest text from the filings of the three companies where they have identified the same risk. 8.1 Risks facing all industries (a) Currency translation and transaction risk may negatively affect our net sales, cost of sales and gross margins and could result in exchange losses. This risk is well understood, affects all industries and hedging options exist to deal with it. But these cost money and where the swings can be as high as 20-40%, the residual risks are not trivial. In fact the progress a company might make in improving the process efficiency can be more than wiped out by an adverse currency swing. But currency swings can also be beneficial - if you are on the right side of them - as has been the case for US producers exporting to the EU market. (b) Our substantial international operations subject us to a number of risks, including unfavourable political, regulatory, labour and tax conditions in foreign countries. From this list the regulatory risks concerned with material recycling (affecting the entire electronics industry) will be of most significance to the solar PV industry but manageable providing they are non-discriminatory. “Protectionism” is probably the highest of the political risks on the horizon. Setting up factories in key markets hedges against this risk. (c) We will need to raise significant additional capital in order to continue to grow our business and fund our operation which subjects us to the risk that we may be unable to grow our business and fund our operations as planned. The credit crunch became a big factor for a company trying to invest its way from its un-virtuous circle to its virtuous circle eg “Thin Film” technologies. But even when the credit market gets back to “relative” normality there is still the usual volatility in the capital markets. Investment flows are often more “sentiment driven” rather than rational and sentiment can be very volatile. A hot technology one day becomes “a dog” the next. At the moment solar PV technology is a hot technology and enjoying a lot of interest from “environmental funds”. The well-publicised shortage of silicon has provided a very favourable backdrop for advocates of

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under our definition of “critical” in shaping; or in shaping the perception of a particular solar PV technology:

• Metallurgical Silicon • Polysilicon • Indium • Tellurium • Gallium • Germanium • Molybdenum • Cadmium

This section of the review finishes with a brief look at some less critical but nevertheless important materials:

• Pastes (and alternatives to pastes) • Glass (and alternatives to glass) • Other widely used materials (backplates and laminate encapsulents) • Light Wavelength Conversion Material (films)

The main workhorse of the solar PV industry remains polysilicon. The price of emerging new thin film technologies is being set to compete with multicrystalline panels. The price of polysilicon panels is driven by the polysilicon supply situation. The price of polysilicon is therefore pivotal for the whole solar PV industry and for this reason we first look in depth at silicon refining technologies.

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resulting in a significant reduction of energy consumption during the manufacturing process and offsets the higher material cost (bromine) through recycling In March 31, 2008 Peak Sun Silicon Corporation, announced that it had closed its Series A round of financing. It plans to complete construction of Phase I of its polysilicon manufacturing plant in Millersburg, Oregon and be operational by the fall of 2008 with a capacity of 50-100 MT per year. The capacity will grow to 5000 MT per year with an additional capital investment of $700 million during Phase II, estimated for completion in 2011. The polysilicon is produced in dense, spherical-bead form with uniform particle size. These qualities make it a suitable feedstock for the continuous-substrate manufacturing processes that can contribute to downstream cost reduction.

2.3.5 Future R&D Directions Mayaterials Inc received a grant of $800,000 in Nov 20008 from the U.S. Department of Energy to try to obtain solar grade silicon from agricultural by-products. 5N silicon has been demonstrated from material precursor. Because the silica extracted from the trace elements of the organic waste is fine grained it may be possible to process at lower temperatures. SINTEF Group and NTNU (Norway) - have been investigating, on a laboratory scale, an electrolysis/electro chemical refining of silicon. In the process the anode is an alloy of copper and silicon (the copper makes it denser), the electrolyte is a mixture of oxides that is less dense than the alloy and the purified silicon is the cathode. SINTEF Group - have also been looking (with ECN of the Netherlands, ScanArc Plasma Technologies AB and Sunergy Investco BV) at a direct metallurgical process they term “SOLSILK”. It involves the use of plasma as the heating source to reduce the silicon followed by a unidirectional solidification process. It is based upon the careful selection of quartz and carbon black to control the boron and phosphorous impurities going into the process. It uses a ¼ of the energy of the Siemens’ process. A 100 MT/year pilot has been built with the research objective of a processing cost of €15/kg ($21/kg). Metalysis - is scaling up and commercialising the Fray-Farthing-Chen (FFC) Cambridge Process. This process extracts metals and alloys from their solid oxides by molten salt electrolysis. Such electrolytic produced silicon is in the form of porous silicon which turns readily into a fine powder with a particle size of a few micrometres, and may therefore offer new opportunities for development of solar cell technology but the current focus of the company is to use the technology to produce tantalum, titanium, alloys and carbides. MIT (USA) - researcher have been attempting to exploit the fact that the impurities in quartz are not uniformly distributed in the quartz, but concentrated in small pockets, called precipitates, and thus could be separated and removed before the melting process to eliminate the need for the purification step. 2.4 Implications for the solar PV industry The polysilicon industry prior to 2004 looked and felt like an oligopoly - a handful of very large concerns determining the productive capacity in the market in a “well behaved” way. The long lead-time to bring more capacity on stream re-enforces this behaviour. Some of the large players had pilot plants with a technology to produce polysilicon at a lower price but perhaps did not feel the competitive pressure to rush to bring them on-stream. Life got even better when the solar PV industry grew in leaps and bounds and generated a significant demand in its own right (as opposed from living off the scraps from the electronics industry) and this had not be predicted by the polysilicon industry. Polysilicon supplies tightened and then went into an acute shortage. Prices of polysilicon rocketed up. This fuelled substantial investments in new polysilicon capacity both by the established players and a number of new entrants. The new entrants included Chinese polysilicon producers. It is unfortunate for the supply chain stability that all this extra capacity came on stream just as the global recession suppressed demand. This chain of events is charted by the spot price of polysilicon below:

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of stock in September 2009. In economic forecasting, identifying a likely event is the easy part but to say when it will happen is pure guesswork. That said our scenario offers a positive prospectus for the CIS and CIGS technologies as the period of volatile (and likely rising prices) occurs when the price of solar PV generated electricity sits well above grid parity and cushioned by a very favourable regulatory underpinning. Towards the back-end of a 15 year business plan will be the time when all solar PV technologies will be expected to be providing electricity at grid parity and that is the very time when indium is likely to be coming in at much more competitive prices.

3.3.4 Is the price of indium a critical issue A view (which may not be shared by manufacturers of CIS or CIGS technology who felt the pain of higher indium prices in 2006-2007) is that prices reaching $600 a kilogram was a good and necessary thing in attracting investment in indium processing capacity (primary and secondary). A major solar PV technology that has to depend upon the scraps from another industry is not a sound long-term place to be, as we have already witnessed with silicon solar PV technology industry that had based its business assumptions on taking the left-over polysilicon not used by the electronics industry. Is the price of Indium a make or break issue? Taking the peak price shown in the table below of $1000/kg together with a usage rate of 0.05g of Indium per Wp leads to a cost of 5c per Wp for the Indium - which we can compare to conventional silicon solar cells that cost 24c for the polysilicon (if the crystalline cell manufacturer can buy their polysilicon at $30/kg and the usage rate is 8g/Wp). 3.4 Indium Suppliers China is now the largest producer of indium in the world and the top 10 Chinese indium exporters (by quantity of government allocated export quotas for 2008) are: Hunan Zhuye Torch Metals Import & Export Co Ltd - http://www.torchmetals.com.cn Liuzhou China Tin Group Ltd - http://www.lzylc.com.cn Nanjing Foreign Economic & Trade Development Co Ltd - http://www.nanchem.com Nanjing Kinyu Electronic Materials Co Ltd Huludai Nonferrouse Metal (Group) Import & Export Co Ltd Nanjing Germanium Co Ltd - http://en.nange.com Xiangtan Zhengtan Non-Ferrous Metals Co Ltd Guangxi Yintai Technology Co Ltd Hunan Jingshi Group Co.Ltd Laibin Debang Industry & Trade Co. Ltd Other indium suppliers include: Dowa Holdings Co Ltd (Japan) - http://www.dowa.co.jp China Minmetals Non-ferrous Metals Co Ltd - http://www.cmnltd.com Hsikwangshan Twinkling Star Co., Ltd - http://www.hksts.com/en Indium Corporation of America (USA) - http://www.indium.com/ Jiangsu Sainty International Group Corp Ltd - http://www.jmet.com/html/company.php Mining & Chemical Products (UK) - http://www.mcp-group.com Norilsk Nickel RAO (Russia) - http://www.nornik.ru Shinko Chemical (Japan) - http://www.shinko-chem.co.jp Teck Cominco Limited (Canada) - http://www.teckcominco.com Umcore (Belgium) - http://www.umicore.com For access to the ENF Industry Directory for the full list of Indium Suppliers - click on the link: http://www.enf.cn/database/materials-indium.html Or paste the above link into your Web browser (alternative route via www.enf.cn)

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7.3 Market Prices and trends 10-Year Price Track of Molybdenum ($/kg)

1999 2000 2001 2002 2003 2004 2005 2006 2007 2008

5.9 5.64 5.2 8.27 811.75 36.73 36.73 70.11 54.62 55 In early 2004, molybdenum prices started to rise rapidly, responding to limited world roasting capacity and growing demand for molybdenum, mainly in stainless steel. The price for 2007 is the mid-year price. The year-end price was nearer $66. China’s high level of steel production and consumption has generated strong internal consumption of molybdenum. This consumption, coupled with production limitations in Huludao, led to reduced Chinese exports in 2006 and 2007, and continued to support historically high molybdenum prices. 7.4 Molybdenum Suppliers ABSCO Materials - http://www.abscomaterials.com Alfa Aesar - http://www.alfa.com/ Atlantic Equipment Engineers - http://micronmetals.rtrk.com/?scid=748678 Beijing Tungsten & Molybdenum Material Factory - http://www.btmmf.com Chengda Chemical Industry Co - http://www.cdhgcn.com Climax Molybdenum Company - http://www.climaxmolybdenum.com ESPI Metals - http://www.espi-metals.com/index.htm Freeport-McMoRan Copper & Gold Inc - http://www.fcx.com/company/who.htm H.C.Starck - http://www.hcstarck.com Luoyang Jianyu Molybdenum & Tungsten Technology Co. Ltd - http://www.lyjymw.cn Luoyang Kewei Molybdenum and Tungsten Co., Ltd - http://lymw.en.ec21.com/ National Electronic Alloys Inc - http://www.nealloys.com/ Negele Hartmetall-Technik GmbH - www.negele-hartmetall.de Plansee AG - http://www.plansee.com Sumitomo Chemical - http://www.sumitomo-chem.co.jp The Tungsten Company - http://www.tungstenco.com/moly.htm Wilbury Metals - http://www.wilburymetals.co.uk Zhengzhou Chida Tungsten & Molybdenum Products Co - http://zhengzhou-chida.fuzing.com/ Zhengzhou Sanhui Tradings Co., Ltd - http://www.zzstc.com For access to the ENF Industry Directory for the full list of Molybdenum Suppliers - click on the link: http://www.enf.cn/database/materials-molybdenum.html Or paste the above link into your Web browser (alternative route via www.enf.cn)

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Care is needed with PECVD to ensure that the plasma does not cause surface damage during deposition. The technology is widely used in the manufacture of solar PV technologies eg for the United Solar triple junction a-Si thin-film cells or Oerlikon equipment for a-Si single or a-Si/µc-Si tandem cells Example Suppliers: Amtech Systems, Inc., Applied Materials, Semco Engineering, SevenStar Electronics, ULVAC, Surface Technology Systems plc, Oxford Instruments, Plasma Dynamics LLC, CORIAL

2.2.6 Electron Cyclotron Resonance CVD (ECRCVD) Electron Cyclotron Resonance CVD (ECRCVD) is a form of PECVD that uses electron cyclotron resonance to produce the plasma. Cyclotron resonance occurs when the frequency of an alternating electric field matches the frequency of electrons orbiting the lines of force of a magnetic field. The plasma densities are higher with ECRCVD than those achieved with conventional RF PECVD. Advantages of ECRCVD: • It causes relatively little layer damage since the plasma source and substrate are well separated; • The operation pressure and plasma potential are low; • Substrate biasing allows for separate variation of plasma current and particle energy; • There is the possibility of in-situ substrate pre-treatment and layer post-treatment; • There are no hot elements or active electrodes; • A higher proportion of the process gas is used; • There is the possibility for upscalling

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(Source: Dimatix)

Obtaining the desired result requires the right combination of: • Substrate structure and surface conditions • Ink material composition • Inkjet printer design • Inkjet printer control parameters that are applied • Post deposition processing The number of pulses applied to the actuator controls the volume of material deposited:

(Source: Dimatix)

The accuracy of the deposited droplets of ink on the substrate is a function of the state of the art of the machine. We show below the data Dimatix provide for their SX3 machine:

(Source: Dimatix)

There are two principal application areas for ink-jet printing technology in solar PV manufacture: • Deposition of metallisation contacts • Deposition of the PV active material

4.3.1 Industry Players The use of inkjet printers in the solar PV industry is relatively new and as it developed a number of inkjet

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laser optics to split the output from one laser into a number of parallel beams - usually 2 to 4. The limit of how many such beams can be formed comes from the fact that splitting a beam reduces (more than pro rata) the available power per beam. Then by mounting a number of such multiple-beam lasers in parallel the total number of lines that can be cut in parallel can be multiplied up. In 2010 the machine with the largest number of scribing lines was 16 but 12 was more prevalent. Scribing Line Width It is desirable to reduce the line width and the smallest line width on the market (Jan 2010) is 10 µm. More typical of the machines on the market the minimum line width is in the range 20 - 30 µm. Positioning and accuracy of scribing line The current state of the art for positioning and accuracy of the scribing line is in the range ±2.5µm to ±10µm. Usually it is more important to maintain an accurate distance between parallel grooves than the absolute position of the groove and this is achieved by on-the-fly calculations to position the next cut position relative to an already cut adjacent groove. Otherwise the calculation is made from the substrate edge. To maintain these sort of accuracies the whole equipment usually has a granite frame to damp any vibrations and air conditioning is necessary to reduce heat expansion of the substrate. For example glass has a coefficient of expansion of 8 µm/ ºC. The laser scriber supply industry is in 3 tiers: Turn-key supplier - This is where the whole factory is supplied by the one turn-key supplier who in turn buys in the laser scriber system. Applied Materials is a notable example where they have had a long standing sub-contract arrangement with Manz Automation. Laser scriber system suppliers - Laser cutting systems are used right across the entire manufacturing industry and there are in turn a proportionately large number of companies making laser cutting system. Around 40 companies have focussed their attention and products on the solar PV industry Around 70% of them will buy in the actual lasers from a specialist manufacturer of laser cutters. Component parts: Laser Manufacturers - Leading suppliers of laser cutters include Rofin-Sinon, Coherent Inc, Spectra Physics and Hans Laser Technology Company. Precision Motion System suppliers - Companies like Parker Hannifin who make a precision air-bearing granite table for laser scribing applications (Gen-5) List of Laser/Scriber Suppliers For access to the ENF Industry Directory for the full list of Laser/Scriber Equipment Suppliers - click on the appropriate link: http://www.enf.cn/database/equipment-film-cutting.html Or paste the above link into your Web browser (alternative route via www.enf.cn)

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(Source: Anwell Solar)

Some notes on TCO Deposition: The material choice for the TCO is shown on the attached table (Source: Ton van Mol PVNET Workshop 2003).

Property In2O3:Sn SnO2:F ZnO:Al

Transmission 95 90 90

Band Gap (eV) 3.7 4.3 3.4 Sheet Resistance Ohms/square 2.5 3-10 5-10

Roughness Negligible Tuneable Medium

Plasma Durability Low Medium High

Deposition Rate Medium High Medium

Relative Cost High Low Low-medium This leads to zinc oxide or fluoride doped tin oxide being the preferred materials for low cost a-Si PV cells. The deposition technologies can be either: • Physical Vapour Deposition (PVD and also known as “sputtering”) or • Atmospheric Pressure Chemical Vapour Deposition (CVD) The Chemical Vapour Deposition process runs at 600-700 deg C and has a typical deposition rate of 20-100nm/s.

c. Laser Scribe P1

The laser cuts lines in the transparent conductive oxide (TCO), in a pattern driven by an X-Y table.

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1. Monocrystalline Solar PV Technology This section groups together the following monocrystalline solar PV technologies: 1.1 “Benchmark” Sawn Wafer Technology 1.2 Thinner Silicon Wafers 1.3 Edge Defined Film-fed Growth Process (EFG) 1.4 String Ribbon 1.5 Back-Contact SunPower Technology 1.6 Sanyo HIT Technology 1.7 Suntech Pluto Technology (variant of the PERL technology) 1.8 n-Type Monocrystalline Silicon PV Cells 1.9 Silicon Sliver Cells 1.10 Spherical Solar Cell Significant advances in using thinner wafers will necessitate serious changes in factory processes (handling, sawing etc). The resulting solar PV cells are likely to emerge as a distinctive technology, which is why we have given a section over to this approach as a placeholder and means of differentiating a step change in monocrystalline PV technology. The term “benchmark” is used to describe the widely used industry standard approach to the manufacture of monocrystalline solar PV cells. 1.1 “Benchmark” Sawn Wafer Technology Introduction Sawn monocrystalline wafers are produced using monocrystalline silicon ingots. Cells produced from monocrystalline wafers have somewhat higher efficiencies, historically one to two percentage points, but are more expensive to produce than multicrystalline wafers. ADVANTAGES • Best efficiency for cells in mass production from a variety of producers • Generated highest electricity within a constrained operating area • Wide industrial eco-system behind the technology • Best proven long life performance

DISADVANTAGES

Relatively high fixed and variable costs Exposed to polysilicon price variations

This sub-section covers the version of the monocrystalline technology used by most companies, hence our reference to “benchmark” technology. Later various proprietary versions of the monocrystalline technology are covered. Market Players Numerous players

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Future R&D Directions • Substantially thinner, 150µm wafers. • Reduction in material usage. The impressive progress to date in reducing the amount of polysilicon for

one Watt of peak power of a solar PV cell is illustrated in the following table:

2004 2005 2006 Industry Average 13.01 11.5 10.5

Evergreen (g/W) 9.3 8.1 5.0 • Evergreen - Four-ribbon technology is under development in Evergreen • Georgia Institute of Technology claims to haves fabricated record high efficiency ribbon Si solar cells

with screen-printed and photolithography defined contacts. String Ribbon cells achieved 15.6% and a high efficiency String Ribbon cell 16.6% with photolithography defined contacts. A two-step RTP firing process was critical in achieving high efficiency screen-printed cells.

• Evergreen have R&D programs underway targeting 16% to 18% efficiency cells 1.5 Monocrystalline - Back-Contact SunPower Technology Introduction Most solar cells have parts of their active area in the shadow of highly reflective metal contact grids or current collection ribbons. Thus part of the sunlight illuminating the solar cells cannot be turned into electricity. By providing this second electrical connection from behind this lost sunlight becomes productive and there is a higher efficiency from the solar cell. The SunPower implementation of this idea uses monocrystalline silicon ADVANTAGES • Top of the range efficiency from a monocrystalline solar cell

DISADVANTAGES

Relatively expensive cost of production Exposed to polysilicon price variations Only one source of supply of the technology

Market Players Sunpower - http://www.sunpowercorp.com Cell and Panel Efficiency NREL give the best in class laboratory cell efficiency as 25%. Panel efficiency can be up to 18% In May 2008 Sunpower announced it had produced a 5 inch cell with an efficiency of 23.4%. In March 2009 Sunpower announced that it had achieved a 20.4% efficiency with large area cells cut from a 165 sq mm ingot and made up into a 1.6 sq m panel with new 96-cell producing 333-watts. The result was confirmed by NREL.

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2. Multicrystalline - Benchmark Silicon Sawn Wafer Technology This section groups together the following poly-silicon solar PV technologies: 2.1 Benchmark 2.2 Back-Contact EWT Technology 2.3 Angle Buried Contact (ABC) Cell 2.4 Selective Emitter Cell 2.5 Light Capturing Ribbon The term “benchmark” is used to describe the widely used industry standard approach to the manufacture of polysilicon solar PV cells. 2.1 Benchmark Silicon Sawn Wafer Technology Introduction Sawn multicrystalline wafers are produced from polycrystalline silicon ingots. This technology had just over 50% of the solar PV market in 2006. They are less expensive to produce than monocrystalline wafers but have slightly lower efficiencies.

ADVANTAGES • Medium efficiency for cells in mass production from a variety of producers • Wide industrial eco-system behind the technology • Less expensive to produce than monocrystalline silicon PV

DISADVANTAGES

Has been exposed to impact of polysilicon shortage Efficiency drops with diffused light and at high ambient temperature

Market Players Many producers For access to the ENF Industry Directory for the full list of crystalline silicon module Suppliers - click on the appropriate link: http://www.enf.cn/database/panels.html Or paste the above link into your Web browser (alternative route via www.enf.cn) Key Raw Materials Polysilicon blocks Cell and Panel Efficiency Cell Efficiency ~ 14-17%. Panel efficiency ~ 12-14%

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3. Thin Film This section groups together the following thin-film PV technologies:

3.1 a-Si Family

Includes single, double and triple junction a-Si Cells 3.2 CIS family technology

3.2.1 CIGS (Copper Indium/Gallium diSelenide) 3.2.2 CIGSS (Cu (In Ga) (S,Se)2 ) 3.2.3 CIS (Cu In Se2) 3.2.4 CISCuT (Cu In S2 on Cu-tape) 3.2.5 a-Si/CIGS four terminal tandem solar cell

3.3 CdTe Family

3.3.1 CdTe 3.3.2 CdTe on Silicon

3.4 5 CTZSS (Copper, Tin, Zinc, Sulfur/or Selenium) 3.5 Crystalline Silicon on Glass (CSG) 3.6 FeS2 (Iron Pyrite) Solar PV Cell

These thin film solar PV technologies belong to the so-called second generation solar PV technology 3.1 a-Si Family (including single, tandem and triple junctions) Introduction Amorphous Silicon (a-Si) cells use a non-crystalline thin-film silicon which has no crystallographic order and therefore has different electrical-optical properties as compared to single-crystal and poly Si but can be used in a thin film and deposited on large area. The technology is sometimes referred to as film-silicon. As a-Si has a direct band gap the film thickness is less than 2µm with this class of technology (see also CSG technology in later section for an absorber thickness of between 2-20µm) ADVANTAGES • Ease of manufacture • Very Low Cost of manufacture • Can be made on lightweight, thin and flexible substrates (eg reel to reel production) • Substantial turn-key supplier support • Better “relative” performance with diffused light and at high temperature than multicrystalline solar PV

DISADVANTAGES

Relatively Low Efficiency Associated greater space for given output and hence higher array cost and weight Amorphous silicon can gradually degrade which can lead to the power output falling by as much as

20% (by a phenomenon called the Staebler-Wronski Effect)

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Johanna Solar/Bosch Solar - Matsushita Ecology Systems - http://panasonic.co.jp/mesc/en Miasole - http://www.miasole.com/product/details.html Nanosolar - http://www.nanosolar.com/7areasofinnovation.htm Nanowin - http://www.nanowin.com/ Pvflex - http://www.pvflex.com/eng/ PV Next - JV Web address not known but partner Ritek is http://www.riteksolar.com/p1-about-1.asp Odersun - Q-Cells - http://cigs.q-cells-moduls.com/en/manufacturing_company/index.html Ritek - See PV Next Shurjo Energy - http://www.shurjo-energy.com Solarion - http://www.solarion.de Solibro - See Q-Cells SoloPower - http://www.solopower.com Solyndra - http://www.solyndra.com Stion - http://www.stion.com Sunshine PV Corp - http://www.sunshine-pv.com/english/About_01.asp TAICIS Solar Energy Co Ltd - http://www.taicis.com/aboutus.asp Wisdom Inc - http://60.249.113.97/wisdom/index.asp Würth Solar - http://www.wuerth-solar.com/web/en/wuerth_solar_2009/Solar_Startseite_neu_aktiv.php Zeba Solar - http://www.zebasolar.com/ Cell and Panel Efficiency In March 2008 NREL developed a CIGS cell (small area laboratory created in a high vacuum) with a record 19.9% efficiency. The Centre for Solar Energy and Hydrogen Research, Germany, achieved in 2009 a 19.6% conversion efficiency using an in-line multi-stage process intended for a 0.5 sq cm active cell area. The result was certified by the Fraunhofer Institute for Solar Energy Systems. The challenge for the commercial producers is to close the gap between the efficiency they achieve with their CIGS material under idea lab conditions and how well they can control the consistency of the active ingredients and electronic quality of materials under production conditions. A few company announcements provide a January 2010 state of play small area maximum efficiencies: Solarion achieved 13.4% CIGS cell on a plastic substrate processed on the company's roll-to-roll pilot production line. The 20cm-wide CIGS cell did not have an antireflective coating (Oct 2009) Ascent Solar has achieved 14.01% efficiency in commercial production with their thin film CIGS material on flexible plastic substrates. This has been confirmed by NREL. They believe this will lead to monolithically integrated modules with efficiency as high as 11.7% Centrotherm are claiming 10% with a road map taking them to 14%. Global Solar Energy Inc achieved 15.45% efficiency for their production CIGS material, 13.2% aperture area efficiency for a module using production line material (confirmed by NREL) and achieved a peak efficiency of 11.7% for production CIGS solar cell strings Nanosolar announced that NREL independently verified several of their cell foils had efficient as high as 16.4% a record both for a printed solar cell and one on foil. Their best production rolls in baseline production process, were achieving higher than 11% median efficiency. Description

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Like to focus on processing advances Annex to Section 3.2 - Consolidated List of CIS technology family manufacturers This class of technology has seen a 50% increase of companies entering the field since the last edition of the ENF Technology Review and relatively few have exited. Many public and private investors have provided the funds to take many start-up companies through their development stage into setting up production lines. For access to the ENF Industry Directory for the full up to date list of CIS/CIGS module Suppliers - click on the appropriate link: http://www.enf.cn/database/panels-cis_family-p.html http://www.enf.cn/database/panels-cis_family-u.html Or paste the above link into your Web browser (alternative route via www.enf.cn) 3.3 Thin film - CdTe Family of solar PV Technology

3.3.1 CdTe technology Introduction Around 2004 it was recognised by a number of companies that CdTe technology had the potential for achieving the lowest production costs amongst thin film technologies that were then ready for commercialisation. Companies had an array of inexpensive options to choose from in CdTe fabrication and there emerged many different ways to make 10% efficient cells.

ADVANTAGES

• The thin-films can be deposited using a variety of different techniques that are widely available • Ease of process control leads to high yields (and hence lower cost) • CdTe has a high absorption coefficient, so that approximately 99% of the incident light is absorbed

by a layer thickness of only 1µm (compared with around 100µm for Si). • Absorbs low and diffuse light and more efficiently converts it to electricity under cloudy weather

and dawn and dusk conditions (as do other thin film technologies relative to C-Si) • Low temperature coefficient (as do other thin film technologies relative to C-Si) DISADVANTAGES

Lower Cell Efficiency: Around 7-10% although First Solar is shipping panels with an average of nearly 11%

Tellurium is a relatively rare metal in demand from a variety of industries. This may be a factor limiting CdTe displacing polysilicon in the long term.

Cadmium raises exaggerated concerns in the solar PV context (as the compound CdTe is a semiconductor which is environmentally stable and non-toxic) but this may lead to pressure for better organised recycling.

Market Players Arendi - http://www.arendi.eu Abound Solar (formally AVA) - http://www.abound.com/ CALYXO/Q-Cells Modules - http://cdte.q-cells-moduls.com/en/index.html Canrom Photovoltaics - http://www.canrom.com/ First Solar - http://www.firstsolar.com Primestar - http://www.primestarsolar.com Sichuan Apollo Solar Science & Technology Co., Ltd - http://www.scasolar.com/english/

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4. Very High Performance PV Cells This section groups together the following High Performance PV technologies:

4.1 Single and Double junction (GaAs) 4.2 Multi-junction (GaAs) 4.3 Indium, Gallium, Nitrogen (Full Spectrum) 4.4 Gallium Nitride/Silicon

The GaAs solar PV technology is often referred to as III-V from the class of semi-conductor used ie 3 valence electrons and 5 valence electrons in their respective crystal lattice structures. 4.1 Single and Double junction (GaAs) Introduction Cells using III-V compounds and having single or double junctions

ADVANTAGES • High efficiency

DISADVANTAGES

Expensive materials Expensive to manufacture (but less than triple junction)

These single junction and double junction cells trades lower efficiency for lower cost relative to the triple junction cells. Market Players Millennium Communication - http://www.m-com.com.tw/en/ Spires Semiconductors - http://www.spirecorp.com/spire-semiconductor/index.php Cell and Panel Efficiency In order to compare like with like Millennium Communications have a triple junction InGaAs/GaAs/Ge product with an efficiency at 1 sun of 27%. The efficiency of their double junction InGaAs/GaAs product is 24% and their single junction GaAs product is 21%. Key Raw Materials Gallium Indium Other Information Information for other sub-sections is broadly the same as section 4.1 Future R&D Directions

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Market Players 3GSolar - http://3gsolar.com/ Aisin Seiki - http://www.aisin.com/csr/environment/development/life.html Dyesol - http://www.dyesol.com Fujikura - http://www.fujikura.co.jp/ie_e.html Konarka - http://www.konarka.com G24i - http://www.g24i.com Greatcell - http://www.greatcell.com (Owned by Dyesol) Hitachi Maxell - http://www.maxell.co.jp/e/corporate/profile.html Nissha Printing Co., Ltd. - http://www.nissha.co.jp Peccell Technologies - http://www.peccell.com/index_e.html Showa Denko K.K. (SDK) - http://www.sdk.co.jp/html/english/group/index.html Solaris Nanosciences - http://www.solarisnano.com/solarenergy.php Solaronix - http://www.solaronix.com Science and Technology Research Partners - http://www.strep.ie/home.htm Sustainable Technologies International - http://www.sta.com.au (now part of Dysol) Timo Technology - http://timo.co.kr/english/ Description Below is the basis structure of a dye sensitised cell.

Other structures are emerging for example tandem dye sensitized solar cells. Cell and Panel Efficiency There are three broad directions the technology is taking that impacts the efficiency one can associated with the dye sensitised solar cell: • There is the pursuit of the highest possible efficiency under laboratory conditions. The record for this

has been reported by Grätzel et al at 11.18% based on the long established ruthenium based dye. • Then on a separate track efforts are being made to find different chemical compounds for the dye that

do not use ruthenium, which is relatively expensive which hitherto has been a trade-off against efficiency - but recent progress has been driving the efficiency of the best of these towards 10%

• Efforts to find cells whose efficiency does not degrade with time eg Solaronix claim 10% efficiency and

separately a 6,000 hour full sunlight stability test.

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developed a method for treating the surface of nanoparticles which greatly improves the efficiency of organic solar cells. The researchers were able to attain an efficiency of 2 percent by using so-called quantum dots composed of cadmium selenide. The photoactive layer of hybrid solar cells consists of a mixture of inorganic nanoparticles and an organic polymer. (2010)

Improved Lifetimes Wake Forest University, US, and the Indian Institute of Technology have found that coating organic solar PV cells with a boron nitride nanotubeloaded polymer at a concentration of 1.5% can significantly improve device lifetime. The ultraviolet part of the spectrum can be devastating to polymer device performance and the Boron nitride materials act as a scattering centre for the incoming radiation. (2008) IMEC, Belgium - has shown that the attachment of the nano-morphology of the polymers to the organic polymers could result in a prolonged operational lifetime of organic solar cells. Experiments in most heterogeneous organic solar cells based on this new material showed no degradation of the efficiency after more than 100 hours whereas reference cells degraded already after a few hours. (2009) IMEC and Cytec are embarking on a research programme to halt the phase segregation photo-active blend of conjugated polymers and fullerene acceptor molecules under the influence of time and temperature. They also intend to develop a barrier encapsulation technology suppress the ingress of extrinsic degradation sources of oxygen and water vapour. (2009-2011) Kyung Hee University, Korea - have studied the lifetime improvement of organic solar cells based on conjugated polymer:fullerene blends using a UV absorbing film. The cell using P3HT and PCBM-71 exhibited a conversion efficiency of ~4.3%, but it decreased with increase in illumination time. The conversion efficiency of the cells with and without UV film decreased to 6.6% and 37.6%, respectively, after 24 h of light exposure under AM1.5. The UV exposure appeared to change the P3HT polymer network such that the defects are generated, resulting in the degradation of cell efficiency. It was found that the conversion efficiency of the cell having a 4 um UV blocking layer is higher than that without a UV layer after 12 h of illumination under 120 mW/cm2. Improving manufacturing processes Université d'Angers and Université Strasbourg have developed an approach based on replacing polymers by conjugated molecules with a clearly defined structure. The purpose is to try to get around the problems with long conjugated polymer chains including synthesis, purification, control of the molecular structure and mass, and the distribution of different lengths of chain (polydispersity). Whereas the conversion efficiencies of the initial prototypes published in 2005 were of the order of 0.20% they have recently succeeded in reaching conversion efficiencies of 1.70%. (2009) University College of Santa Barbara, Center for Polymers and Organic Solids have reduced reaction time from 48 hours to 30 minutes, and increased average molecular weight of the polymers by a factor of more than 3. This was achieved by: • replaced conventional thermal heating with microwave heating, • modified reactant concentrations and • varied the ratio of reactants by only 5% from the nominal 1:1 stoichiometric ratio normally employed in

polymerization reactions. The reduced reaction time effectively cuts production time for the organic polymers by nearly 50%, since reaction time and purification time are approximately equal in the production process, in both laboratory and commercial environments. (2009) IMEC, Belgium has demonstrated a fully solution-processed organic solar cell, including a spray-coated active layer and a spray-coated metal top contact. The resulting cell shows power conversion efficiencies above 3%. The active layer is a spray-deposited mixture of the organic semiconductors P3HT and PCBM, overlaid with ink made from nanometre-scale silver particles, fused by heating. (2009) National Institute of Standards and Technology have been working on a means of ensuring that the polymer network in an organic solar PV cell reaches the bottom of the ink film (to absorb electrons) and fullerenses reaches the top (to collect electrons) as the ink hardens. They applied X-ray absorption measurements to the film interfaces and found fullerenes were repulsed and the polymer attracted - the right

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University of Notre Dame - has assembled cadmium selenide (CdSe) quantum dots in a single layer on the surface of nano films and tubes made of titanium dioxide (TiO2). Anchoring CdSe quantum dots on TiO2 nanotubes allowed them to create an ordered assembly of nanostructures. The researchers used four different sizes of quantum dots (between 2.3 and 3.7 nm in diameter) to produce absorbent peaks at different wavelengths (between 505 and 580 nm). (2008) California Institute of Technology (Caltech) are using arrays of long, thin silicon wires embedded in a polymer substrate to created a solar cell that absorbs up to 96% of incident sunlight.Each wire measures between 30 and 100 microns in length and only 1 micron in diameter and the structures are square centimeters in size to hundreds of square centimeters ie the size of a normal cell." 5.4 Multi-junction Nanowire PV Cells Introduction Honda Motor Company have patented an approach that combines compound semi-conductors with nanowires and in terms of the exploitation of the full potential this approach, might qualify more of a 4th Generation solar PV technology. Market Players Honda Cell & Panel Efficiency No figures have been published but the aim of the researchers is to overtake the 40% plus efficiency figures of the III-V triple junction cells covered in an earlier section. Description The cell comprises 20 nano-metre columns to prevent the occurrence of defects and reduce the distortion from a difference in lattice constants between the five different semi-conductor materials.

The GaP layer does not act as a junction but instead prevents defects from arising between the substrate and the initial growth of nanowires. Raw Materials Indium and Gallium but in small quantities

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approximately 1,000 W/m², the value which is used as a basis for calculating the output of normal flat panel PV systems. But very few CPV companies are giving out information on the efficiency of their CPV systems and the two that do so are giving an AC efficiency, whereas for normal flat panel PV technologies the efficiency is a DC efficiency. Industry “specification” standards still have a way to go for CVP systems. The next best comparisons is to look at some of the basic metrics of the CPV systems that affect the power output and here the picture improves considerable in terms of the available data. The main factors of comparison are the extent of concentration and the module efficiencies of the solar PV cells. With all HCPV systems some form of tracking is essential so the performance of the tracker becomes relevant. We have tried to build up a picture of the HCPV industry based upon these three metrics:

Company Concentration Ratio

PV Module Tracking Accuracy

Aavid Solar 10 mono- silicon ±0.2°

Arima Ecoenergy

476 Triple Junction GaAs Cell Efficiency ≥35%

± 0.3°

Amonix 500 Triple Junction GaAs Best module efficiency 27.6% System AC efficiency 25%

Changzhou Huayin

200 to 500 GaAs Cell efficiency 35%

Chengdu ZSun 10 to 300 ±0.5°

Compound Solar

300 to 700, 800 GaAs:efficiency:40% CPV efficiency:25%

±0.5°

Concentration Solar la Mancha

500 Cell type not specified Efficiency ≥30% (?)

±0.2°

Concentrix Solar GmbH

500 III-V Triple-Junction Average Module Efficiency 27.2% System DC efficiency 25% System AC efficiency 25%

±0.1°

Cool Earth Solar

300 to 400 No tracking (?)

CPower 25 mono- silicon 90% performance for ±4.0°

Energy Innovations

1200 Triple-junction Module Efficiency 29%

Emcore 500 Triple-junction Cell efficiency 39%

Entech 20

ES System 1100 and 1600 versions

III-V Triple Junction 23.24 and 26.3% module efficiency versions

Everphoton Energy

500 to 1000 customised

III-V Triple Junction Cell efficiency 35% module efficiency ~ 27%

±0.1° open loop ±0.05° closed loop

Green and Gold Energy

1370 Cell efficiency ~ 40% module efficiency ~ 31%

±0.1° open loop

Greenvolts 500 III-V Inverted Metamorphic

Guascor Foton 400 Cell efficiency 27%

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• Cools PV cells to more efficiency operating conditions • High overall efficiency by exploiting waste heat

DISADVANTAGES

Same disadvantages of PV only CPV systems More complex installation as hot water (as well as electricity) has to be connected to customer’s

services

Harnessing the waste heat from the solar PV cells seems obvious from an engineering and environmental viewpoint but it is not from a marketing viewpoint. The additional installation complexity of plumbing the hot water into the existing heating system in a building creates a market entry barrier that will make it harder for this technology to achieve rapid scale economies. Market Players Absolicon Solar - http://www.absolicon.com BrightPhase Energy - http://www.brightphaseenergy.com DiSP - http://www.disp.co.il (Web site no longer functioning) GreenField Solar - http://www.greenfieldsolar.com Menova Energy - http://www.power-spar.com/Power-Spar/index.php SHAP - http://www.shap.it/ENG/default.htm Skyline Solar - http://www.skyline-solar.com Solenza - http://www.solenza.co.nz ZenithSolar - http://www.zenithsolar.com Cell and Panel Efficiency The extraction of heat from the systems makes it less easy to make direct comparisons with other CPV systems. Description Absolicon Solar -consists of a cylinder-parabolic reflector that concentrates the light of the sun ten times onto the receiver. It is equipped with solar thermal and photovoltaic panels and a solar tracking system. Company claims a total energy output of 40-50%.

BrightPhase Energy - Photensity™ is designed specifically for single story commercial premises and provides light (through louvres), heat (left over by the solar PV cells and carried away by glycol fluid circulating in the louvres) and electricity (PV cells on back of louvres getting concentrated light reflected from adjacent louvres)

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Schott Solar - Production capacity for their laminated glass not visible. Wurth Solar - Meets specific customer requests Xsunx - Employing a phased roll out, they plan to grow the capacity to over 100MWp by 2010. Future R&D Directions New energy Technologies have developed a new process for spraying organic PV cells onto glass using a PV material in which compounds have replaced opaque metals in order to improve the transparency of the PV cells on glass (See Organic Solar Cells)

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6. Other Innovations 6.1 Light Wavelength Conversion Films and Luminescent solar concentrators

6.1.1 Europium Japan's National Institute of Advanced Industrial Science and Technology (AIST) gave details in March 2008 of their light wavelength conversion material using europium. AIST are claiming an efficiency improvement of 1.75%

(Source: AIST)

The europium complex absorbs the ultraviolet part of sunlight and emits fluorescence after converting the UV light ((250-500nm) to the higher wavelength region (750nm). The project was carried out in collaboration with Sanvic Inc (a manufacturer of solar cell sealing materials). The Eu complex molecules are kneaded into the ethylene vinyl acetate (EVA) sealing material to create beads. The beads were formed into EVA sealing sheets with a thickness of 0.6mm and a width of 115cm. The sheets have been applied to silicon PV solar cells and installed on the roof of Sanvic's Hosoe Plant to evaluate the durability of the material. Whilst it is still a research product - its significance is that it could be applied to a number of solar PV technologies and for this reason it has been given its own section.

6.1.2 Mentarix Mentarix Pte Ltd is a start up (in which seed fund BAF Spectrum Pte Ltd has a 30% stake) which is developing a film to be applied to any PV cell to provide an efficiency improvement of up to 20% of its original efficiency.

6.1.3 Covalent Solar Covalent Solar is a start-up (spun out by team at the MIT) that has announced a “concentrating” solar photovoltaic technology based upon organic dyes laid on glass. In their approach light is absorbed by a dye coating on a sheet of glass and re-emitted laterally to the edge of the glass where solar PV cells convert the light to electricity. One dye collects all the absorbed light from its surrounding dye molecules. Another dye molecule used, known as molecular phosphors, is extremely transparent to its own light emission. This reduces the transmission loss to the edge of the glass.

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(Source: SunPower)

(Source: SunPower)

3.3 Two-axis Mounts Dual-axis systems can track through both the vertical and horizontal axis, therefore achieving a more precise orientation towards the sun. The efficiency gains for dual-axis systems are typically in the range 35%-40%. The performance of dual-axis trackers are less sensitive to latitude as they can be tilted to face North or South. In 2009 the largest manufacturer of dual-axis trackers is believed to be ADES with 150MW already installed, followed by is Meca Solar (partner of ET Solar) and then Solon.

(Source: ADES)

3.4 Tracker Drives Tracker drives can be broadly divided into:

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term sustainable market.

Car Air Purifier Water Irrigation

System Rotating Decorative Crystal

Caravan De-humidifier

Water Treatment- Reverse Osmosis

Hat Mounted Fan Oxygen Bar Portable Fan Rotating Clothes

Frame Line Rotating Display Table

Car Ventilation Fan Perfume Dispenser Rotating

Globe Rotating Hanging Basket Hook

Swinging Object Display

Toy - Innovative Toy - Traditional Water

Oxygenation Solar Powered Inshore Boat

Ventilation Fan

Water Pump Garden Water Sprouter

Bird Bath

An excellent example of this simplicity is a water pump that provides a feature for a garden pond. In general people want to view the feature in daylight and that is exactly when the solar PV cells deliver the necessary power. Water oxygenation and cooling fans are further examples. The hat-mounted fan, at a first glance, might be seen as a novelty that raises a smile, a few sales but never quite catches on in the mainstream summer hat market. On the other hand in a hot and humid country it provides a steady stream of air to cool the forehead and the alternative of a hand fan has been around for centuries. From a technology standpoint it does not make the same demands on the solar cells that customers for building applications might demand of a 20 year life-time guarantee and there for is a market open to new unproven low cost solar PV technologies. Another neat example of usage mapping onto the solar PV energy strengths and limitations is the solar powered boat for purely inshore (near to beach) holiday locations. 3.3 Solar Cells Plus Battery Plus Motor Adding a battery into the mix of solar cells plus motor opens a new class of application that needs to have occasional electricity on demand (whether the sun is shining or not) but the usage is not intensive. We might

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5. Feedback from the field The most important quality feedback loop comes from customers back to the original manufacturer via the installers and distribution channel since this is where corrective action can be taken for any fault arising from the design of a solar module. Where faults are more generic to a technology then a more industry wide approach is useful and NREL has established Photovoltaic Module Field Failure Database. They have gathered together a list of recurring faults which we have extracted and listed below under each technology, in alphabetical order and most of which normal factory inspection and testing will have ironed out from products released from the factories: General Issues Across all Technologies Bypass diode failure Corrosion leading to loss of grounding Delamination Glass fracture Improper insulation leading to loss of grounding Inverter reliability Moisture ingress Quick connector reliability Wafer Silicon Busbar adhesion degradation, electrical contact, etc. Cracked cells (bonding processes, strain, etc.) Effect of glass on encapsulant performance Fatigue of ribbon interconnect Front surface soiling Glass edge damage of frameless modules (though installation, handling, etc.) Junction box failure (poor solder joints, arcing, etc.) Light-induced cell degradation Mechanical failure of glass-glass laminates Reduced adhesion leading to corrosion and/ or delamination Slow degradation of ISC Solder joint or gridline interface failure (increased series resistance) Thin Film Silicon Annealing instabilities (a-Si) Electrochemical corrosion of SnO2:F Initial light degradation (a-Si) CdTe Busbar adhesion degradation, electrical contact, etc. Cell layer integrity- back contact stability Cell layer integrity- interlayer adhesion and delamination; electrochemical corrosion of SnO2:F Fill-factor loss (increased series resistance and/ or recombination) Shunt hot spots at scribe lines before and after stress Weak diodes, hot spots, nonuniformities before and after stress CIS Busbar failure - mechanical (adhesion) and electrical Cell layer integrity - contact stability Cell layer integrity - interlayer adhesion Cell-to-cell interconnect (discrete cells)

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ENF research category: I Research focus: funding and coordinating across 46 designated research centres Contact: SC.BES@science.doe.gov Florida Solar Energy Centre - PV Materials Web site: http://www.fsec.ucf.edu/en/research/photovoltaics/materials/index.htm ENF Research category: II Research focus: Development of CuIn1-xGaxSe2-ySy (CIGSS) thin film solar cells for terrestrial and space applications Contact: James M. Fenton Georgia Institute of Technology, University Center of Excellence for Photovoltaics - Web site: http://www.ece.gatech.edu/research/UCEP/ Research focus - screen-printed and photolithography defined contacts on; nanowire structured hybrid cells; String Ribbon cells. Partner in Center for Interface Science: Solar Electric Materials Contact: ajeet.rohatgi@ece.gatech.edu Havard University Web site: http://www.harvardscience.harvard.edu/directory/programs/school-engineering-and-applied-sciences ENF Research category: II Research focus: partner in the Centre For Energy Efficient Materials (CEEM); partner in the Center for Excitonics Contact: Evelyn L. Hu Indiana University, Purdue University Indianapolis (IUPUI) Web site: http://www.chem.iupui.edu/ ENF Research category: II Research focus - synthesis of quantum dots. Contact: jasiegel@iupui.edu Iowa State University, Electrical and Computer Engineering Web site: http://www.ece.iastate.edu/who-we-are/faculty-and-staff/faculty-new/index/detail/abc/297.html ENF Research category: II, V 3, V 5.2 Research focus - metallic photonic crystal back-reflectors using photolithography and reactive-ion etching and deposited a-Si:H solar cells; new silicon alloys; organic molecules can be used in solar applications Contact: vdala@iastate.edu

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University of Michigan Web site: http://cstec.engin.umich.edu/ ENF Research category: II, V 5.2, V 5.3 Research focus (1): coordinate Center For Solar And Thermal Energy Conversion (CSTEC); inorganic PV with low dimensional materials, including arrays of quantum dots and rods; thin-film systems comprising: novel small molecules; conjugated linear chain polymers; dendritic and caged molecules in which the chemical functionalities can be controlled. Alternatives to ITO for use with organic solar cell on flexible substrates; Solar-grade silicon from agricultural by-products Contact: pfgreen@umich.edu University of Minnesota, Department of Chemistry Web site: http://www.chem.umn.edu/groups/blank/research.html Also: Institute on the Environment; Mechanical Engineering, Solar Energy Laboratory ENF Research category: II Research focus: partner in the Center for Advanced Solar Photophysics(CASP); Energy and charge transfer dynamics in materials and model systems related to photovoltaics (solar cells) Contact: blank@umn.edu University of North Carolina - Center for Solar Fuels and Next Generation Photovoltaics Web site: http://www.advancedmaterials.unc.edu/ ENF Research category: V 5.3 Research focus: structurally preformed molecular assemblies and composites, with emphasis placed on the fundamental processes (e.g. energy transport, charge separation, etc.) that are common to solar fuels and photovoltaic technologies Contact: T.J. Meyer (Director), V. Ashby, M. Brookhart, J. DeSimone, C. Fecko, M. Forbes, W. Lin, R. Lopez, L. McNeil, A. Moran, R. Murray, J. Papanikolas, G. Papoian, L.C Qin, E. Samulski, C. Schauer, J. Templeton, M. Waters, W. You, M. Yousaf, Y. Wu University of Notre Dame Web site: http://cbe.nd.edu/faculty/show/pkamat/ ENF Research category: V 5.2, V 5.3 Research focus - Assembly of cadmium selenide (CdSe) quantum dots in a single layer on the surface of nano films and tubes made of TiO2. Contact: kamat.1@nd.edu University of Pittsburgh Web site: http://www.engr.pitt.edu/chemical/research/index.html ENF Research category: II

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ENF Research Category: II, V 2, V 3, V 4, V 5.1, V 5.2, V 5.3 Research focus - tandem DSC cells; Spectral Changes of Polysilane Thin Films by Heat Treatment; SiGe Solar Cells with Precisely Controlled Heterojunctions; Development of Si-Ge-Sn Thin Film Solar Cells; Fabrication of InAs Quantum Dot Advanced Light Management Technology for Thin-Film Multi-Junction Solar Cellss for Solar Cell Applications; Low-Photon-Energy Conversion with Narrow-Gap Molecular Donor-Acceptor Compounds; Plasmon-Induced Electron Transfer at Au/TiO2 Nanoparticle iInterface for Solar Cell Application; Bonding Technology for Thin-Film Multi-Junction Solar Cells; Near-Infrared Transparent Conductive Oxide for Thin-Film Multi-Junction Solar Cells Contact: Tel: (+81)-29-861-2000 National Institute for Materials Science Web site: http://www.nims.go.jp/eng/units/p05_solar-cell.html ENF Research Category: V 4 Research focus - Development of Top Solar Cell Using III-V Nitride Thin Film Contact: apvc@nims.go.jp Niigata University Web site: http://www.niigata-u.ac.jp/index_e.html ENF Research Category: II, III Research focus - P-type Transparent Conductive Oxide Films Prepared by Solution Method and Sputtering Method Contact: kokusai@adm.niigata-u.ac.jp Osaka University Web site: http://www.osaka-u.ac.jp/en/research/katsudo.html ENF Research Category: III, V 3, V 5.3 Research focus - Electrochemical Deposition of Compound Semiconductors for Thin-Film Solar Cells; Optical Managements in Thin Film Solar Cells by Localized Surface Plasmon; Crystal Growth Control of Electrically Conductive Thin Films on the Nanopatterned Substrate Contact: contact@uic.osaka-u.ac.jp Ritsumeikan University Web site: http://www.ritsumei.ac.jp/eng/research/research_more_info/index.htm#18 ENF Research Category: V 3 Research focus - Design of Thin-Film Full Spectrum Solar Cells and Development of Cu(In,Al)S2 Top Cells Contact: Suzaku Campus Tel: (+81)-75-813-8146 Kinugasa Campus Tel: (+81)-75-465-8229 Biwako-Kusatsu Campus Tel: (+81)-77-561-3946

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and their efficient, sustainable manufacturing technology; epitaxially growing single junction GaAs and dual junction InGaP/GaAs solar cells on germanium substrates using an improved manufacturing technology; optimizing the process of stacking the top and bottom cells, and of handling the thinned-down top cells; improving thermophotovoltaic technology by using high-efficiency, low-bandgap Ge cells to produce cells that are highly efficient and stable under high fluxes of infrared radiation; EU Project POLYSIMODE, Improved multicrystalline-silicon modules on glass substrates; EU project THINSI, Thin Si film based hybrid solar cells via powder on substrate; EU project ULTIMATE - Ultra thin Si solar cells for module assembly -tough and efficient; EU project SOLASYS, New laser sources for PV manufacture; EU project HETSI, heterojunction solar cells based on a-Si c-Si; EU Project CrystalClear, lower-cost, high-efficiency and reliable silicon solar modules; EU project FACESS, flexible autonomous cost efficient energy source (organic solar PV) and storage; EU project PRIMA, plasmon resonance for improving the absorption of solar cells; thermophotovoltaic technology by using high-efficiency, low-bandgap Ge cells Contact: Katrien.Marent@imec.be Universiteit Gent Web site: http://www.ugent.be/nl/univgent/faculteiten/overzicht.htm/faculties?ugentid=TW ENF Research Category: II, V 3 Research focus - EU project Athlete, large-area chalcopyrite modules with improved efficiencies and on the up-scaling of silicon-based tandem solar cells; EU project COCOON, conformal coating of nanoporous materials Contact: Tandem solar cells: Marc.Burgelman@UGent.be Nanoporous materials: Christophe.Detavernier@UGent.be University of Hasselt, IMO-IMOMEC Web site: http://www.imo.uhasselt.be/ ENF Research Category: V 5.2 Research focus - new generation of organic PV having better efficiency (>= 5%) on 1cm² glass substrate; Contact: Dirk.Vanderzande@uhasselt.be VITO (Flemish institute for technological research) Web site: http://www.vito.be/VITO/EN/HomepageAdmin/Home/WetenschappelijkOnderzoek/Energietechnologie/ ENF Research Category: II, VIII Research focus - EU Project N2P (3D nanostructures) Contact: Dirk Fransaer Vrije Universiteit Brussel, (University of Brussels) Web site: http://tona.vub.ac.be/Tona/ ENF Research Category: V 5.2 Research focus - Nanostructuring, morphological stability, and mechanism of charge transfer in conjugated polymer/fullerene blends for organic photovoltaic cells.

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Web site: http://www.zsw-bw.de/index.php?id=38 ENF Research Category: III Research focus - EU project Alpine, advances in laser technology for scribing PV cells; Contact: info@zsw-bw.de Greece Ethniko Idryma Erevnon, National Hellenic Research Foundation (NHRF) Web site: http://www.eie.gr/index-en.html ENF Research Category: II Research focus - EU project COPET, control of photo-induced energy transfer in functionalized carbon nanostructures towards design of nanoscale applications; Contact: Tel: (+30)-2107-273700 University of Patras Web site: http://www.upatras.gr/index/page/id/88 Research focus - large-area chalcopyrite modules with improved efficiencies and on the up-scaling of silicon-based tandem solar cells (EU Athlete project) Contact: Tel: (+30)-2610-997120, (+30)-2610-997100 Hungary Magyar Tudomanyos Akademia, (Academy of Sciences) Web site: http://www.mta.hu/index.php?id=752 ENF Research Category: V 3, V 5.3 Research focus - EU Project N2P (3D nanostructures); EU project HIGH-EF, Large grained, low stress multi-crystalline silicon thin film solar cells on glass; EU project ROD-SOL- all-inorganic nano-rod based thin-film solar cells on glass Contact: István BÁRSONY: barsony@mfa.kfki.hu Ireland Dublin Institute of Technology Web site: http://dublinenergylab.dit.ie/dublinenergylab/researchprojects/solarenergy/ ENF Research Category: Research focus - EU project Ephocell, Smart light collecting system for the efficiency enhancement of solar cells Contact: Dr Sarah McCormack

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investigations into the structure and dynamics of the most widely used conjugated polymers (poly-3-alkyl-thiophenes) Contact: etsii@upct.es Universidad de Castilla-La Mancha, Campus de la Fábrica de Armas Web site: http://www.uclm.es/centro/ ENF Research Category: V 5.1 Research focus - synthesis of new organic dyes for efficient light-harvesting materials in molecular photovoltaic devices; EU project NANOSOL, from femto- to millisecond and from ensemble to single molecule photobehavior of some nanoconfined organic dyes for solar cells improvement Contact: Tel: (+34)-902-204-100 Universitat Jaume I (Photovoltaic and Optoelectronic Devices Group) Web site: http://www.uji.es/UK/content/estructura_acad/634296-634316.html ENF Research Category: V 5.1, V 5.2, V 5.3 Research focus - nanotube dye solar cell; DSC organic dyes; CdSe quantum dot sensitised cell; Characteristics of P3HT:PCBM solar cell; Contact: barea@fca.uji.es Universidad Politecnica de Madrid Web site: http://www.upm.es/portal/site/internacional/ ENF Research Category: V 5.1, V 4 Research focus - EU Project CrystalClear Lower-cost, high-efficiency and reliable silicon solar modules; EU Project Fullspectrum, new PV wave (full spectrum) making more efficient use of the solar spectrum; EU project IBPOWER, Intermediate band materials and solar cells for photovoltaics with high efficiency and reduced cost Contact: Sra. D.ª Carmen Pérez Nadal Universidad Politecnica de Valencia Web site: http://www.upv.es/investigacion/estructuras-investigacion-es.html ENF Research Category: II Research focus - EU project Silicon_Light Contact: informacion@upv.es Sweden Chalmers Tekniska Hoegskola (Chalmers University of Technology) Web site: http://www.chalmers.se/ap/EN/ ENF Research Category: II

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Annex - ENF Classification of Research into Solar PV Technologies We have followed the layout of this Future Solar PV Technology Review as the means of classifying the various research areas of focus: I - Social, Economic & Political Resarch II - Critical Materials III - Key machines IV - Factory Processes V - PV Technology cells and panels

1 Monocrystalline Solar PV Technology 2 Multicrystalline - Benchmark Silicon Sawn Wafer Technology 3. 2nd Generation - Thin Film 4. Very High Performance III-V PV Cells 5. Third Generation

5.1 Dye Sensitised 5.2 Third Generation - Organic Polymer 5.3 Nano-technology (Quantum dots)

6. Concentrator PV Technology (CPV)

VI Thermo PV Technology (TPV) VII Innovative Solar PV Films, Cells, Panels & Designs

1. Transparent Solar Cells 2. Coloured Solar PV Modules 3. Innovative Panel Designs (Roof Tiles and Shingles) 4. Combined PV Flat Panel and Thermal Water Heating 5. Other Innovations

VIII - Solar PV Generated AC Energy

1. Inverters 2. Charge Controllers 3. Mounts and Trackers 4. Batteries 5. BIPV

IX - The Solar Powered Products Revolution X - Quality and Reliability of Solar PV Systems

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PEDOT:PSS - a polymer mixture of two ionomers. One is made up of sodiu polystyrene sulfonate. The other is PEDOT, an intrinsically insoluble polymer poly(3,4-ethylenedioxythiophene), which can be chemically or electrochemically doped. PERC cell - Passivated Emitter and Rear Cell architecture in which the rear surface of a monocrystalline cell is passivated by silicon dioxide to enhance the efficiency PERL cell - Passivated emitter, rear locally diffused cell is similar to the PERC architecture but an additional diffusion of boron taken place just under the rear contacts and this further increases the efficiency of the cell. Phosphorus-oxychloride - Used to diffuse phosphorus (with five valence electrons) into silicon (with four valence electrons) so that the extra electron in the lattice creates n-type silicon. Photon - the basic "unit" of light energy Photovoltaic-Thermal (PV/T) System — A system that both converts sunlight into electricity and collects heat energy for water or space heating purposes Plasma is a gas in which a certain portion of the particles are ionized Plasma PVD - Plasma Physical Vapour Deposition more commonly known as Sputtering Plasmons are density waves of electrons created when light hits the surface of a metal under precise circumstances. These density waves can be harnessed to couple additional light into a PV cell that would not otherwise be absorbed and increase PV cell performance. PL Band - Photoluminescence (PL) range of the spectrum PLUTO cell - A proprietary mono-silicon solar PV cell developed by Suntech building on some of the principals of the PERL cell p-n junction - the boundary zone resulting from fusing a p-type semi-conductor with an n-type semi-conductor in which holes from the p-type semi-conductor drift across the boundary into the n-type semi-conductor and electrons from the n-type semi-conductor drift across the boundary into the p-type semi-conductor. Photons from light irradiance stimulate a surplus of holes and electrons in this junction region to produce a voltage that is able to deliver an electric current around a circuit connected to the respective two semi-conductors Polishing & Grinding - Machine to ultra smooth the surfaces of silicon wafers just after they have been cut from the silicon ingots Polyene - an alternative dye to TiO2 for dye sensitised solar PV cells Polymer solar cells - solar PV cell made from organic semi-conducting polymers Polyphenylene vinylene - a conducting polymer of the rigid-rod polymer host family. Polysilicon - The principle material used in the manufacture of all silicon solar cells that comes from purifying metallurgical silicon (which is only 98-99% pure) to usually 99.9999% pure or 6N grade silicon Polythiophene - results from the polymerisation of thiophenes, a sulfur heterocycle, that can become conducting when electrons are added or removed via doping. PTF - Polymer Thick-Film silvers p-type semiconductor - semiconductor that has had tiny amounts of another semi-conductor diffused into it (doped) which has one less valence electron per atom than the host semi-conductor and therefore finishes up with gaps in the lattice structure which produces positive-type holes that can readily accept electrons from an external source Puller - Machine used to gradually lift a seed of mono-crystalline silicon out of a melt of multi-crystalline polysilicon in order to grow a rod of mono-crystalline silicon