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.
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.
