High-efficiency, 0.79 M/sup 2/ tandem a-Si modules fabricated by a batch process

In this work, we've successfully developed the high efficiency, 0.79 m/sup 2/ a-Si/a-Si tandem modules with average stable power of 50 watts by a EPV's production line at Bangkok Solar Co., Ltd. in Thailand. Films are deposited on 48 pieces of glasses at a time. This can be achieved for the first time by using 1) microcrystalline n-layer for better interface contact and lower absorption. 2) ZnO/AI back electrode deposited at room temperature. 3) High quality p/i interface layer. Furthermore, we could also successfully reduce the cell fabrication time about 40% by introducing the treatment after p-layer deposition for lower boron cross contamination at the p/i interface.