Fabrication technologies for large-area plastic-film-substrate solar cells

We have been developing large-area a-Si-based solar cells on plastic-film substrates. For further improvement in throughput, we tried to increase the deposition rates of the top a-Si cell and the bottom a-SiGe cell. Based on our previous work, we investigated the relation among the deposition conditions, peak-to-peak voltage of applied power and the stabilized efficiencies of small-area single-junction cells fabricated on the film. As a result, we obtained a-Si and a-SiGe single-junction cells with deposition rates of over 20 nm/min. They were applied to large-area a-Si/a-SiGe double-junction cells to achieve a stabilized efficiency of 8.0%.