Amorphous silicon solar cells fabricated by photochemical vapor deposition

Hydrogenated amorphous silicon solar cells were fabricated by photochemical vapor deposition. Wide optical band-gap (∼2.0 eV) hydrogenated amorphous silicon carbide was employed for the p layer. Acetylene (C2H2) or dimethylsilane (Si(CH3)2H2) was used as a carbon source instead of methane which is usually used in a glow discharge process. Although p, i, and n layers were deposited in a single reaction chamber, the solar cell showed high-energy conversion efficiency of 8.29% under AM1, 100-mW/cm2 insolation. The distribution of boron atoms in the solar cell was analyzed by secondary ion mass spectroscopy. The boron content in the i layer was of the order of 1016 cm−3. This is comparable to that in the i layer of the solar cell fabricated by the glow discharge system with separated three reaction chambers.