World's largest amorphous silicon photovoltaic module

In order to reduce costs for thin film Si photovoltaic solar, large area VHF plasma CVD technology was developed. Two VHF voltages which had the phase difference controlled by the phase-shifter are supplied to the both ends of an electrode, which is successful in getting time-averaged uniformity of VHF voltage on the electrode. Using the frequency of 60 MHz, the a-Si film with the deposition rate of 1.7 nm/s ± 18% was prepared on a 1.4 m × 1.1 m glass substrate. A plasma CVD apparatus with 5 deposition chambers configured in a star shape was fabricated for the production of a-Si solar modules. 728 modules of 1.4 m × 1.1 m were manufactured during the long-run producing test in which deposition and plasma-cleaning were repeated. 93% of total modules manufactured in this test had electric outputs that were included within ± 2% of the deviation of the average module output.