8/10/2019 solar cell tarun.pptx

http://slidepdf.com/reader/full/solar-cell-tarunpptx 1/12

8/10/2019 solar cell tarun.pptx

http://slidepdf.com/reader/full/solar-cell-tarunpptx 2/12

8/10/2019 solar cell tarun.pptx

http://slidepdf.com/reader/full/solar-cell-tarunpptx 3/12

Photovoltaic Roadmap 

1st Generation PV

Crystalline Silicon

2nd Generation PV

Thin Film

3rd Generation PV

Ultra-High Efficiency

Ultra-Low Cost

Source: European Commission meeting Dec. 2004

8/10/2019 solar cell tarun.pptx

http://slidepdf.com/reader/full/solar-cell-tarunpptx 4/12

Types of PV cells

Silicon Crystalline Cells Thin Film Cells

made by using crystalline silicon

solar cells developed from themicroelectronics technology

industry.

made by depositing one or

more thin layers (thin film)of photovoltaic material on a

substrate.

Mono Crystalline PV Cells

Multi Crystalline PV Cells

Amorphous Silicon

PV Cells

Poly Crystalline

PV Cells

(Non-Silicon

based)

8/10/2019 solar cell tarun.pptx

http://slidepdf.com/reader/full/solar-cell-tarunpptx 5/12

Single Crystal solar cells in panel

• Silicon solar cells are made using either single crystalwafers, polycrystalline wafers or thin films

• approx. 1/3 to 1/2 of a millimeter thick

• The silicon must be of a very high purity and have anear perfect crystal structure

Polycrystalline solar panel

• Polycrystalline wafers are made by a casting process

Amorphous-Si solar panel

• Amorphous silicon, one of the thin film technologies

8/10/2019 solar cell tarun.pptx

http://slidepdf.com/reader/full/solar-cell-tarunpptx 6/12

FABRICATION

Single Crystal solar cells

Single crystal wafers are sliced from a large single crystal ingot

It is a very expensive process

The silicon must be of a very high purity and have a near perfect crystal

structure

Polycrystalline solar Polycrystalline wafers are made by a casting process

molten silicon is poured into a mould and allowed to set

Then it is sliced into wafers

 it is not as efficient as monocrystalline cells

The lower efficiency is due to imperfections in the crystal structure resultingfrom the casting process

 Amorphous-Si solar  

 Amorphous silicon is one of the thin film technologies

It is made by depositing silicon onto a glass substrate from a reactive gas

such as silane (SiH4)

8/10/2019 solar cell tarun.pptx

http://slidepdf.com/reader/full/solar-cell-tarunpptx 7/12

8/10/2019 solar cell tarun.pptx

http://slidepdf.com/reader/full/solar-cell-tarunpptx 8/12   e    8    /    P

    P    A    S   o    l   a   r    P    V    D   e   s    i   g   n    I   m   p    l   e   m   e   n    t   a    t    i   o   n    O    &    M 

    M   a   r   s    h   a    l    l    I   s    l   a   n    d   s    M   a

   r   c    h    3    1  -    A   p   r    i    l    1    1 ,

    2    0    0    8

8

• Crystal cell (Single crystal and Poly crystalline Silicon)

Single crystal Poly crystalline

1-1-2. Various type of PV cell

Formed by melting high purity

silicon like as Integrated Circuit

For mass production, cell is sliced

from roughly crystallized ingot.

8/10/2019 solar cell tarun.pptx

http://slidepdf.com/reader/full/solar-cell-tarunpptx 9/12

Thin Film Technology

Silicon deposited in a continuous manner on a base materialsuch as glass, metal or polymers.

Thin-film crystalline solar cell consists of layers about 10μm thickcompared with 200-300μm layers for crystalline silicon cells.

PROS

• Low cost substrate and

fabrication process.

CONS

• Not very stable .

8/10/2019 solar cell tarun.pptx

http://slidepdf.com/reader/full/solar-cell-tarunpptx 10/12

Amorphous Silicon PV Cells The most advanced of thin film technologies .

 Operating efficiency (3-5)% . 

 Makes up about 13% of PV market .

 very cheap and used in calculators. 

PROS

• Mature manufacturing

technologies available .

•Light and flexible, so can be

used for a wide range ofapplications.

CONS

• Initial 20-40% loss in

efficiency .

8/10/2019 solar cell tarun.pptx

http://slidepdf.com/reader/full/solar-cell-tarunpptx 11/12

The Single rystalline Silicon Solar ell

•  Pure silicon is a poorconductor of electricity

• “Doping” of silicon with phosphorus and boron is

necessary to create n-typeand p-type regions

• This allows presence of free electrons and electron-

 free „holes‟  • The p-n junction generates

an electric field that actsas a diode, pushingelectrons to flow from the

 P side to the N side

8/10/2019 solar cell tarun.pptx

http://slidepdf.com/reader/full/solar-cell-tarunpptx 12/12

Poly Crystalline PV Cells( Non – Silicon Based Technology )

PROS

 16% laboratory efficiency

6-9% module efficiencyCONS

Immature manufacturing process

Unlike most other II/IV material CdTe exhibits direct band

gap of 1.4eV and high absorption coefficient