High efficiency amorphous/microcrystalline silicon solar cell fabricated on metal substrate

High efficiency amorphous/microcrystalline silicon solar cell fabricated on stainless steel substrate have been developed by using a multi-chamber system in which all layers can be deposited without breaking the pressure on 30 cm x 40 cm area. The detailed cell structure is hot Ag/ZnO/n(muc-Si)-i(muc-Si)-p(a-Si) or p(muc-Si)/ZnO/n(mu c-Si)-i(a-Si)-p(muc-Si)/ITO. New type of electrode has been developed in order to achieve good film uniformity. It was found that the microcrystalline bottom cell with thicker n(muc-Si) layer fabricated by VHF shows better cell performance. Higher frequency of VHF is more preferred. By optimizing p(muc-Si) and the interface of bottom cell and the intermediate ZnO, an initial efficiency of 14.5% (Voc=1.49V, Jsc=13.7 mA/cm(2), FF=0.711) has been achieved on 3 cm(2) active cell area. The prototype module with module efficiency of 8% has been achieved.