Extremely High-Rate Deposition Of Silicon Thin Films Prepared By Atmospheric Plasma Cvd Method With A Rotary Electrode

The high-rate deposition of a-Si:H films for the photovoltaic layer of solar cells prepared by an atmospheric pressure plasma CVD method with a rotary electrode was investigated. VHF (150 MHz) atmospheric pressure plasma is generated at the narrow gap of less than 1 mm between the rotary electrode and the substrate. The atmospheric pressure and VHF plasma enable high-rate deposition and a reduction in ion damage to the growing surface. A large volume of the mixed gas can be supplied with high uniformity by the high-speed rotation of the electrode. A deposition rate of 10 Angstrom/s - 200 Angstrom/s was obtained for a 100 mm, x 100 mm substrate, while maintaining conductivity and photosensitivity up to 200 Angstrom/s. The efficiency of a-Si:H solar cells was found to be independent of deposition rate for proper hydrogen dilution ratios (10 < H-2/SiH4 < 100). Based on this result, an initial efficiency of 8.25 % was obtained for an a-Si:H p-i-n solar cell with the i-layer prepared at the deposition rate of 81 Angstrom/s.