Hitoshi Nishio

Thin-Film Polycrystalline Si Solar Cell on Glass Substrate Fabricated by a Novel Low Temperature Process

Thin film polycrystalline Si solar cells on glass substrates were fabricated by the excimer laser annealing of heavily boron doped a-Si and the subsequent deposition of polycrystalline Si on them by plasma-enhanced chemical vapor deposition at low temperature. The resistivity of the heavily boron doped laser annealed polycrystalline Si film is as low as 2×10-4 Ωcm. The structure of the solar cell presented here is ITO/n µc-Si:H (30 nm)/p poly-Si (2 µm)/p+ poly-Si (300 nm)/glass substrate, which shows reasonably high current density despite the low-temperature fabrication. The effective diffusion length of this solar cell estimated from the evaluation of the inverse quantum efficiency is more than or equal to the thickness ( 2 µm) of the solar cell.

Thin-film polycrystalline Si solar cell on glass substrate fabricated by a novel low temperature process

Thin film polycrystalline Si solar cells on glass substrates were fabricated by the excimer laser annealing of heavily boron doped a-Si and the subsequent deposition of polycrystalline Si on them by plasma-enhanced chemical vapor deposition at low temperature. The resistivity of the boron doped laser annealed polycrystalline Si film reaches to the 2/spl times/10/sup -4/ /spl Omega//spl middot/cm, which shows a strong (111) preferred orientation. The structure of the solar cell presented here is ITO/n /spl mu/c-Si:H (30 nm)/p poly-Si (2 /spl mu/m)/p/sup +/ poly Si (300 nm)/glass substrate, which shows sufficiently high current density despite the low-temperature fabrication. This sufficiently high Jsc is postulated to be both due to the hydrogen passivation of the grain-boundary and the low carrier concentration of poly-Si film by low temperature fabrication.