Silicon heterojunction solar cells with plated contacts for low to medium concentration photovoltaics

Silicon heterojunction (SHJ) technology enables high performance photovoltaics at acceptable cost. In this article, we show that this technology is also well suited for low to medium concentration applications. For this purpose, SHJ cells have been optimized and tested at different illumination levels and temperatures. An interesting increase of the efficiency temperature coefficient is observed with increasing illumination level. This behavior translates in improved performances of the tested SHJ devices under low to medium concentration applications, when operated at temperature above 25°C. This is linked to the behavior of the FF, exhibiting an improvement with increasing temperature while the cell is operated under high illumination level. This phenomenon suggests thermally assisted carrier transport through a barrier probably located at the TCO/p+ a-Si:H interface.