Sandwich-Doping for a Large Schottky Barrier and Long-Term Stability in Graphene/Silicon Schottky Junction Solar Cells

Doping is an effective method for controlling the electrical properties and work function of graphene which can improve the power conversion efficiency of graphene-based Schottky junction solar cells (SJSCs). However, in previous approaches, the stability of chemical doping decreased over time due to the decomposition of dopants on the surface of graphene under ambient conditions. Here, we report an efficient and strong p-doping by simple sandwich doping on both the top and bottom surfaces of graphene. We confirmed that the work function of sandwich-doped graphene increased by 0.61 eV and its sheet resistance decreased by 305.8 Omega/sq, compared to those of the pristine graphene. Therefore, the graphene-silicon SJSCs that used sandwich-doped graphene had a power conversion efficiency of 10.02%, which was 334% higher than that (2.998%) of SJSCs that used pristine graphene. The sandwich-doped graphene-based silicon SJSCs had excellent long-term stability over 45 days without additional encapsulation.

Automated summary

A new sandwich doping method has been reported to effectively enhance the work function and reduce sheet resistance of graphene, leading to improved power conversion efficiency in graphene-silicon solar cells. These sandwich-doped graphene-based silicon solar cells exhibit significantly higher efficiency and excellent long-term stability without additional encapsulation.