High growth rate and gas utilisation in a-Si:H solar cells made with amplitude modulated VHF-CVD

We have incorporated amorphous silicon i-layers made by amplitude modulated VHF plasma CVD into n-i-p solar cells. The cell efficiencies are similar to those obtained with standard device quality continuous wave (CW) a-Si:H i-layers, but at a high growth of 0.55 nm/s and gas utilization rate of /spl sim/50%. Due to the combined effect the efficient use of the SiH/sub 4/ is roughly 10 times better while the defect density (/spl sim/3-8/spl times/10/sup 15/ cm/sup -3/) and photosensitivity (4-6/spl times/10/sup 5/) of the a-Si:H material are not compromised. This happens in spite of the fact that higher silane radicals contribute significantly to the growth.