Amorphous solar cell on multilayer of SnO2/ZnO TCO substrate for full spectrum splitting solar cell application

Abstract

To increase the performance of thin film solar cells, the solar spectrum splitting technique has been considered and studied. It was found from the simulation that the total efficiency of nearly 25% can be obtained at the splitting wavelength of 614 nm with the top cell using higher band gap material. The experiment has been carried out to verify the simulation results. Up to now a total efficiency of about 22.0% has been obtained using hydrogenated amorphous silicon (a-Si:H) and Cu(In1-x,Ga-x) as the top and bottom cells, respectively, at a splitting wavelength of 620 nm. In this study, we have developed a multilayer of transparent and conductive oxide (TCO) substrate of a-Si:H solar cell with better electrical properties especially improved fill factor and better electrical compatibility. This multilayer TCO is suitable for the splitting technique to enhance the performance at the short-wavelength of the top cell.