a-Si Basis Heterojunction Stacked Solar Cells

Abstract

ABSTRACTA systematic study has been made on a-Si basis heterojunction tandem structure solar cells. Design rule and optimizations of cell parameters on two and three stacked heterojunction solar cells are discussed on various material bottom junctions stacked with a-Si. A series of experimental trials has been made on some candidate materials. Technical data on cell fabrication processes, device performance are presented. In the -present stage of experiments, 13.3% efficiency on a-Si/poly-Si two terminals tandem solar cell and also on a-Si//poly- CdS/CdTe four terminals cell have been obtained. Some key technologies for future low cost massproduction processes such as growth of polycrystalline thin film for bottom cell are also discussed.