Enhanced photovoltaic effect in graphene–silicon Schottky junction under mechanical manipulation
Dong Pu, Muhammad Abid Anwar, Jiachao Zhou, Renwei Mao, Xin Pan, Jian Chai, Feng Tian, Hua Wang, Huan Hu, Yang Xu
Abstract
A graphene–silicon Schottky junction (GSJ), which has potentials of large-scale manufacturing and integration, can bring new opportunities to Schottky solar cells for photovoltaic (PV) power conversion. However, the essential power conversion limitation for these devices lies in a small open-circuit voltage (Voc), which depends on the Schottky barrier height. In this study, we introduce an electromechanical method based on a flexoelectric effect to enhance the PV efficiency in GSJ. By atomic force microscope (AFM) tip-based indentation and in situ current measurement, the current–voltage (I–V) responses under a flexoelectric strain gradient are obtained. The Voc is observed to increase for up to 20%, leading to an evident improvement of the power conversion efficiency. Our studies suggest that the strain gradient may offer unprecedented opportunities for the development of GSJ-based flexo-photovoltaic applications.