2 Wednesday 12th November
2014 TCO Workshop, University of Liverpool
Transparent Conducting Oxides – from an industrial perspective
•How are TCO’s made on an Industrial Scale?
•How are TCO’s used in Industry?
Liam Palmer, NSG Group
3
Liam Palmer – [email protected] Advanced Technologist, On-line Coatings
NSG European Technical Centre Lathom, Lancs. UK.
European Technical Centre, Lathom
Wednesday 12th November
2014 TCO Workshop, University of Liverpool
NSG Group R&D Facility
Wednesday 12th November
2014 TCO Workshop, University of Liverpool 4
Global Flat Glass Market
• Global market for flat glass in calendar year 2011 was approximately 59 million tonnes.
• At the level of primary manufacture, this represents a value of around €24 billion.
• Most of the world’s float glass goes into buildings. Automotive applications account for around 10 percent.
Wednesday 12th November
2014 TCO Workshop, University of Liverpool 5
NSG Group
• Principal operations in 30 countries
• Ownership/interests in 48 float lines
• Employs around 28,000 people
• Sales in 130+ countries
• €54million investment in R&D in FY2013
• The NSG Group is one of four glass groups producing around 50 percent of the world’s high quality glass.
World-leading supplier of ultra-thin glass for smart
phones and tablet devices. Our Ultra Fine Flat Glass (UFF) is produced in thicknesses as
low as 0.3-1.1mm. NSG annual report 2013
‘Making a Difference to
our World through
Glass Technology’
Expansion of Value-Added Business
Wednesday 12th November
2014 TCO Workshop, University of Liverpool 7
High value-added products will drive future growth
The Float Glass Process
• Pilkington float process is at the heart of the worldwide industry.
• Operates non-stop for 10-15 years
• 6000 km/year
• 0.3 mm-25 mm thick, up to 3 m wide
Wednesday 12th November
2014 TCO Workshop, University of Liverpool 8
Melting
furnace
Float
bath
Cooling
lehr
Continuos
ribbon of
glass
Cross
cutters
Large plate lift-
off devices
Small plate lift-
off devices
Raw material feed
Wednesday 12th November
2014 TCO Workshop, University of Liverpool 9
Transparent Conducting Oxides
• TCOs are used wherever electrical conductivity and transparency are required
• Different applications use different aspects of the TCO properities
• Thin film solar cells make use of the electrical conductivity to collect electrons generated by the photoactive materials
• Glazing applications make use of the high reflectance at long wavelengths
Wednesday 12th November
2014 TCO Workshop, University of Liverpool 10
• Low-Emissivity and Solar Control Coatings
• In a double glazed unit, a low-emissivity coating on the inner pane blocks radiative heat trying to escape into the cavity
Low-Emissivity and Solar Control Coatings
Wednesday 12th November
2014 TCO Workshop, University of Liverpool 11
• A wide variety of coating technologies are utilised by the glass industry
– Spray Pyrolysis
– Powder Spray
– Chemical Vapour Deposition
– Sputter Coating
– Thermal Evaporation Coatings
– Sol Gel Coatings
• These are applied
– On Line i.e. as the glass is produced on the float line
– Off Line i.e. coating not necessarily produced at the same location
Manufacturing a Functional Coating
Wednesday 12th November
2014 TCO Workshop, University of Liverpool 12
Variations of CVD
• Atmospheric Pressure – APCVD • Low Pressure - LPCVD • Metalorganic – MOCVD • Aerosol Assisted – AACVD • Combustion/Flame – CCVD • Hot Wire/Filament – HWCVD/HFCVD • Plasma Enhanced - PECVD • Laser Assisted – LACVD • Microwave Assisted – MWCVD • Atomic Layer Deposition – ALD
Broadly termed thermal CVD methods
Broadly termed activated CVD methods
3 Main TCO’s
• FTO – Fluorine doped Tin Oxide
• Manufactured by Atmospheric Pressure Chemical Vapour Deposition (APCVD)
• ITO – Indium doped Tin Oxide
• Manufactured by Sputtering, Physical Vapour Deposition (PVD)
• AZO – Aluminium doped Zinc Oxide
• Manufactured by Low Pressure Chemical Vapour Deposition (LPCVD), Plasma Enhanced Chemical Vapour Deposition (PECVD) or Atomic Layer Deposition (ALD)
Wednesday 12th November
2014 TCO Workshop, University of Liverpool 13
Wednesday 12th November
2014 TCO Workshop, University of Liverpool 14
Chemical Vapour Deposition
Animation kindly supplied by Dr. Warren Cross, University of Leicester
Wednesday 12th November
2014 TCO Workshop, University of Liverpool 15
Chemical Vapour Deposition
Main gas flow region
Gas Phase Reactions
Surface Diffusion
Desorption of
Film Precursor
By Products
Diffusion
to surface
Wednesday 12th November
2014 TCO Workshop, University of Liverpool 16
CVD on Glass
For on-line coating of glass we require:
• High growth rates – required thickness in <2 s
• Stable chemistry – uniform coatings for continuous operation for many days
• Good adhesion to glass
• High efficiency – reduce costs
Wednesday 12th November
2014 TCO Workshop, University of Liverpool 17
APCVD Strengths and Weaknesses
Strengths Weaknesses Result
On-line coating possible
Reduced flexibility Reduced labour costs, high volume manufacture
Fresh substrate surfaces
No washing step, enhanced adhesion
High deposition rates Need to match line speed
Thick films possible with high throughput
Hard films Improved processability and performance
Structure control possible e.g. crystallinity
Rough surface Improved functional properties and durability
Volatile precursors required
Limited range of materials
Wednesday 12th November
2014 TCO Workshop, University of Liverpool 22
On-Line Coating Position
Load raw
materials
Float line Process
TCO Coated glass supply chain
On-line APCVD
T 650°C
1500 oC
Melting 600 oC
1050 oC
Floating
Cooling
Turbulent Flow CVD Coater
Wednesday 12th November
2014 TCO Workshop, University of Liverpool 23
Topcoat Beam RHS Section View
TunnelSkirtAir curtain
SkirtAdjust
Air curtaininlet pipe
Water cooling
In out
Slot1 Slot2
Glass flow
Exhaust manifoldassembly
Extraction slot
Downstreamwater box
Wednesday 12th November
2014 TCO Workshop, University of Liverpool 24
• SnCl4 + H2O + HF SnO2:F + HCl (~1.5 at% F)
• Much gas phase reaction
• Gases introduced separately in turbulent flow regime
• Very high growth rates >100 nm/s possible
• Low precursor efficiency <10%
SiCxOy (70 nm)
SnO2:F (350 nm)
Glass
• SiH4 + C2H4 + CO2 SiCxOy + H2O + other by-products
• Used as colour suppression and barrier layer
CVD of SnO2:F – Pilkington K Glass™ a Low-E Coating
Wednesday 12th November
2014 TCO Workshop, University of Liverpool 25
Low Emissivity Coating – Pilkington K Glass™
• SiCO under layer used as a blocking layer and colour suppressant
Wednesday 12th November
2014 TCO Workshop, University of Liverpool 26
Laminar Flow CVD Coater
Glass
Glass Ribbon Flow
Up-Stream Exhaust
Down-Stream Exhaust
Precursor gases
Outside Atmosphere
CVD of SnO2:F – Common Precursors
• Tin Oxide Precursors
• Dimethyl Tin Dichloride (DMT)
• Monobutyl Tin Trichloride (MBTC)
• Stannic Chloride (SnCl4)
• Fluorine Dopant Precursors
• Hydrogen Fluoride (HF)
• Trifluoro Acetic Acid (TFA / TFAA)
Wednesday 12th November
2014 TCO Workshop, University of Liverpool 27
Challenges Facing On-Line Coatings
• Delivering precursors at a constant temperature and flow.
• Maintaining a constant uniformity across a 3 metre ribbon at a speed of up to 15 m/min for as long as possible.
• Longest coatings run time is currently ~60 hours.
• Quality Control – Continuously Inspecting and Monitoring the product being produced.
• Warehouse and other ‘cold-end’ activities.
Wednesday 12th November
2014 TCO Workshop, University of Liverpool 28
3 Main TCO’s
• FTO – Fluorine doped Tin Oxide
• Manufactured by Atmospheric Pressure Chemical Vapour Deposition (APCVD)
• ITO – Indium doped Tin Oxide
• Manufactured by Sputtering, Physical Vapour Deposition (PVD)
• AZO – Aluminium doped Zinc Oxide
• Manufactured by Sputtering, Low Pressure Chemical Vapour Deposition (LPCVD), Plasma Enhanced Chemical Vapour Deposition (PECVD) or Atomic Layer Deposition (ALD)
Wednesday 12th November
2014 TCO Workshop, University of Liverpool 29
The Sputtering Process
+ -
Ar Ar+ e-
Pumps Process Gas
Wednesday 12th November
2014 TCO Workshop, University of Liverpool 30
Typical Plant Layout – for Continuous Coating
Coating Zone Transfer
Chamber
Transfer
Chamber
Load
Lock
Washing
Machine
Inspection
Room
Exit
Lock
Glass Transport Direction
Vacuum Plant
Sp
ee
d
Position
Leading Edge Speed
Wednesday 12th November
2014 TCO Workshop, University of Liverpool 32
Sputtering Plant – OLC1
• £16 million cost for the coater
• £40 million cost for the entire site installation.
• Able to coat ‘Jumbo’ sized plates (6m x 3.21m).
• Able to coat ~10 million m2 a year.
• Ability to produce single and double silver coatings.
• Single silver coatings for Low-E products.
• Double silver coatings for Solar Control products.
• No TCO’s are made at this coater, due to RTP process.
• Able to make TCO’s but not viable as produce FTO.
Wednesday 12th November
2014 TCO Workshop, University of Liverpool 35
Comparison – SnO2:F vs ZnO:Al
• ZnO:Al offers better optical and electronic properties over SnO2:F
• After etching AZO significantly enhances light scattering (for silicon devices)
• SnO2:F is more stable than AZO in chemical durability tests.
• SnO2:F is cheaper and more durable than ZnO:Al
Wednesday 12th November
2014 TCO Workshop, University of Liverpool 36
Coated Products
• Coated Products Divided into 3 groups;
Wednesday 12th November
2014 TCO Workshop, University of Liverpool 38
Building Products
• Low Emissivity
• Solar Control
• Functional Products
NSG TEC™ Products
• Electronic display apps.
• White goods market (freezer lids, etc.)
• OFC Substrates
Solar Products • Conductive substrates for solar cell
fabrication.
Pilkington Energy Advantage™
• Pilkington Energy Advantage™ is a low emissivity coating sold predominantly into colder areas of the United States and is basically Pilkington K Glass™ made using oil cooled beams.
• Different precursor chemistry, same end result. Main difference for the end user is slightly more hazy than Pilkington K Glass™ – though we can’t sell Pilkington Energy Advantage™ as Pilkington K Glass™ .
• Low emissivity feature reduces heat loss from a building by reflecting heat back into the building.
• Emissivity is the measure of how efficient the coating is at reflecting heat.
• Clear glass allows ~89% of heat to escape, Pilkington Energy Advantage™ only ~15%.
Wednesday 12th November
2014 TCO Workshop, University of Liverpool 39
Pilkington Energy Advantage™
• Pilkington Energy Advantage™ / NSG TEC™ 15 coating is made up of three layers.
Wednesday 12th November
2014 TCO Workshop, University of Liverpool 40
Pilkington Energy Advantage™
Wednesday 12th November
2014 TCO Workshop, University of Liverpool 41
Pilkington Energy Advantage™
coating
Pilkington Eclipse Advantage™
• Product is a Solar Control coating designed to reduce solar heat from entering a building.
• Designed for commercial building applications and produced on a range of tints to provide aesthetic performance.
• Tint colour is seen from outside of building and not obscured by coating.
• Solar control performance changes with tint.
• Predominantly used on surface #2 of an IGU though can be used as a single pane.
• Glass side reflection dictates how the product looks from the outside.
Wednesday 12th November
2014 TCO Workshop, University of Liverpool 42
Pilkington Eclipse Advantage™
• Pilkington Eclipse Advantage™ is made up of four layers.
Wednesday 12th November
2014 TCO Workshop, University of Liverpool 43
Pilkington Eclipse Advantage™
Wednesday 12th November
2014 TCO Workshop, University of Liverpool 44
Pilkington Eclipse Advantage™
Coating on #2 Surface
NSG TEC™ Products
• NSG TEC™ products developed as a spin off from Pilkington Energy Advantage™ for electronic applications.
• Currently used as;
• Transparent, electrically conductive articles - i.e. heated freezer cabinets.
• TCO Substrates for additional devices – i.e. LCD displays.
• TCO products are basically a variation of top F:SnO2 layer to give different sheet resistance values or morphology.
• Originally made to order products for specific customers but formed the basis of the Solar Energy portfolio.
Wednesday 12th November
2014 TCO Workshop, University of Liverpool 45
NSG TEC™ Glass Applications
• Thin Film Photovoltaics
• Electrochromic Mirrors
• Commercial Refrigeration
• Oven Windows/White Goods
• Heated Glass
• Displays
• Sodium blocking for sputter coating processors
• Thermochromics
• Lighting
• Numerous other specialty applications
Wednesday 12th November
2014 TCO Workshop, University of Liverpool 46
NSG TEC™ Glass Properties
Wednesday 12th November
2014 TCO Workshop, University of Liverpool 47
NSG TEC™ Product
Available Thickness
(mm)
Sheet Resistance
(Ohms/square)
Visible Transmittance
(%)
Haze
(%)
Hemispherical Emittance
NSG TEC™ 7 2.2, 3.0, 3.2 6 - 8 80 – 82 5 0.12
NSG TEC™ 8 2.2, 3.2 6 - 9 80 – 81.5 12 0.12
NSG TEC™ 15
2.2, 3.0, 3.2 12-14 82 – 83 ≤0.35 0.15
4.0, 5.0, 6.0, 8, 10 12-14 83 – 84.5 ≤0.75 0.15
NSG TEC™ 20 4.0 19 - 25 80 – 85 ≤0.8 0.21
NSG TEC™ 35 3.2, 6.0 32 - 48 82 – 84 ≤0.65 0.34
NSG TEC™ 50 6.0 43 - 53 80 – 85 ≤0.55 0.38
NSG TEC™ 70 3.2, 4.0 58 - 72 82 – 84 0.5 0.45
NSG TEC™ 250 3.2, 4.0 260 - 325 84– 85 0.7 0.67
NSG TEC™ 1000 3.2 1000 - 3000 88 0.5 0.78
NSG TEC™ Products for Solar Applications
• Solar products are based around the Pilkington Energy Advantage™ system with variation in either layer thickness or chemistry.
• Products tend to be manufactured for a single customer rather than same product for multiple customers.
• Products generally form the base plate for solar cells with customers then adding further coatings on top of our materials.
• Solar customers are very strict in terms of specifications and defects – need to qualify the product with each customer.
• Also need products to be exactly the same across each of the manufacturing sites to improve logistics.
Wednesday 12th November
2014 TCO Workshop, University of Liverpool 48
NSG TEC™ Glass Properties
• NSG TEC™ products used in the majority of thin film PV technologies.
• TCO properties, optimised for each PV technology.
• Light transmission.
• Coating conductivity.
• Haze.
Wednesday 12th November
2014 TCO Workshop, University of Liverpool 49
Thin film silicon NSG TEC™A8 High haze, rough coating
TCO coating
Surface roughness
CdTe NSG TEC™C15 Low haze, smooth coating
TCO coating
Surface roughness
NSG TEC™ Glass Appliance Applications
Wednesday 12th November
2014 TCO Workshop, University of Liverpool 50
Commercial Refrigeration and Freezer Applications
Passive Active Curved
NSG TEC™ Glass Appliance Applications
Wednesday 12th November
2014 TCO Workshop, University of Liverpool 51
Commercial Food Warmers
Oven Door Glass
Touch Panel Technology - Resistive
• Resistive touchscreens use a flexible outer membrane that, upon user touch, forms an electrical circuit with the glass substrate.
Wednesday 12th November
2014 TCO Workshop, University of Liverpool 52
Glass
TEC 1100 – High Resistance Coating
Resistive Coating
Protective Coating
Flexible Membrane
Insulating
Spacers
Glass
TEC 1100 – High Resistance Coating
Resistive Coating
Protective Coating
Flexible Membrane
Insulating
SpacersNSG TEC™
Touch Panel Technology - Capacitive
• Capacitive coupling between a conducting surface and the users finger draws current from the surface to determine the touch-point in capacitive screens.
Wednesday 12th November
2014 TCO Workshop, University of Liverpool 53
Glass
TEC SB - Silica Layer
Conductive Coating – TCO (ITO or other)
sodium
Protective Coating
Glass
TEC SB - Silica Layer
Conductive Coating – TCO (ITO or other)
sodium
Protective Coating
NSG TEC™
Touch Panel Applications
Wednesday 12th November
2014 TCO Workshop, University of Liverpool 54
Video Gaming Systems
Airport Check-In Terminals GPS Systems
NSG TEC™ Glass in Heated Windows
• The use of NSG TEC™ Glass for other heated applications is increasing
• Restaurants and residences in cold climates are increasing the comfort level surrounding picture windows.
• Eliminates the cold-shoulder effect with radiant heat.
• Reduces heat loss through the windows and the need to over-heat the entire room to compensate.
• Maintains window clarity and preserves spectacular views.
• Eliminates condensation.
Wednesday 12th November
2014 TCO Workshop, University of Liverpool 55
Heated Window Applications
• Residential Application – Exterior
• Photo and Application – Courtesy of Radiant Glass Industries LLC
Wednesday 12th November
2014 TCO Workshop, University of Liverpool 56
Heated Window Applications
• Residential Application – Interior
• Photo and Application – Courtesy of Radiant Glass Industries LLC
Wednesday 12th November
2014 TCO Workshop, University of Liverpool 57
Heated Window Applications
• Restaurant Application - Mahogany Grille, Durango Colorado
• Photos and Application – Courtesy of thermique™
Wednesday 12th November
2014 TCO Workshop, University of Liverpool 58
Industrial Transportation
• Can incorporate active or passive defrosting capability in many applications;
• Military vehicles
• Tank Turrets
• Humvees
• Marine Glazing
• Military
• Private Yacht
• Locomotive glass
• Siemens & General Electric (GE)
Wednesday 12th November
2014 TCO Workshop, University of Liverpool 59
NSG TEC™ Glass in Electrochromics
• Increasing activity in large area commercial electrochromic development
• Much more difficult application than EC mirrors
• Smart window systems are in development for increased energy management
• Layered film solutions are also in development
• Large scale producers:
• Sage
• View Inc.
Wednesday 12th November
2014 TCO Workshop, University of Liverpool 61
Electrochromic Applications
• Photo and Application – Courtesy of Sage Electrochromics, Inc.
Wednesday 12th November
2014 TCO Workshop, University of Liverpool 62
• Club Porticello - Oconomowac, Wisconsin
• Overlooks scenic lake
• Windows face west into setting sun
• Need to preserve view while keeping diners comfortable
Electrochromic Applications
• Photo and Application – Courtesy of Sage Electrochromics, Inc.
Wednesday 12th November
2014 TCO Workshop, University of Liverpool 63
Summary
• Shown common manufacturing methods for 3 of the main TCO materials;
• Fluorine doped Tin Oxide (FTO) – manufactured by APCVD.
• Indium doped Tin Oxide (ITO) – manufactured by Sputtering.
• Aluminium doped Zinc Oxide (AZO) – manufactured by Sputtering, LPCVD, PECVD or ALD.
• Shown an incite into industrial applications of Transparent Conductive Oxides;
• Low-E, Solar Control and Technical Applications.
• Shown some of the products offered by NSG that use TCO’s.
Wednesday 12th November
2014 TCO Workshop, University of Liverpool 64
Thank you for you attention