The enhanced efficiency of graphene–silicon solar cells by electric field doping

Abstract

The graphene–silicon (Gr–Si) Schottky junction solar cell has been recognized as one of the most low-cost candidates in photovoltaics due to its simple fabrication process. However, the low Gr–Si Schottky barrier height largely limits the power conversion efficiency of Gr–Si solar cells. Here, we demonstrate that electric field doping can be used to tune the work function of a Gr film and therefore improve the photovoltaic performance of the Gr–Si solar cell effectively. The electric field doping effects can be achieved either by connecting the Gr–Si solar cell to an external power supply or by polarizing a ferroelectric polymer layer integrated in the Gr–Si solar cell. Exploration of both of the device architecture designs showed that the power conversion efficiency of Gr–Si solar cells is more than twice of the control Gr–Si solar cells. Our study opens a new avenue for improving the performance of Gr–Si solar cells.