TYPES OF SOLAR CELLS

PV cells are made of semiconductor materials. The major types of materials are crystalline silicon and thin films, which vary from each other in terms of light absorption ability, energy conversion efficiency, manufacturing technology, and cost of production.  

1) CRYSTALLINE SILICON

 A. Mono-crystalline Silicon cell

•    Manufactured by sawing wafers from a  very pure single  and continuous cylindrical crystal of silicon with zero defect and impurities.

•    Most efficient (~15%–20% modules commercial) and most expensive.

 

 B. Poly-crystalline Silicon cell

•    Manufactured by sawing wafers from an ingot of melted and re-crystallized silicon (cast Si) of multiple small crystals.

•    Less efficient (12%–15% modules typical), but less expensive than mono-crystalline, and manufacturing process is simpler.

 

2) THIN FILM

A. Amorphous Silicon  cell 
Manufactured as a thin film of deposited disordered Si on glass or metal (flexible) substrates.
Less efficient (8%–10%), but less expensive than crystalline silicon.



B.  Other  thin Film cells 
These have higher efficiency than amorphous silicon cell and are in the beginning commercial stage. Among
these are: 

• Cadmium Telluride (CdTe)—An efficient light absorbing material. The most commercially available of the
   thin films; modules ~11% efficiency. 
• Copper Indium Gallium Diselenide (CuInSe2)—The highest efficiency thin-film cell/module:
   12%–13%. 
• Organic Solar Cells—Thin film of organic semiconductor, Polymer, polyethylene, etc. early stage of development, potentially the least expensive.