Interfacial Band Engineering of Highly Efficient PEDOT:PSS/p‐Si/ZnO Heterojunction Solar Cells

Hybrid heterojunction solar cells (HHSCs) using different active materials as hole‐selective transport layers and electron‐selective transport layers show great potential in both low cost and high power conversion efficiency (PCE). Herein, PEDOT:PSS/p‐Si/ZnO backcontact heterojunction solar cells are prepared using the simple low‐temperature solution method. PEDOT:PSS is introduced into p‐Si‐based solar cells as an antireflective and passivation layer to optimize device performance. The effect of the work function (WF) of ZnO on device performance is investigated, and a PCE of 10.74% is achieved using low‐WF ZnO. In addition, the PEDOT:PSS layer is doped with Nafion, and the surface passivation quality of the p‐Si is dramatically enhanced. By optimizing the doping concentration of Nafion, the PCE of the optimized device reaches 11.43%, which is currently the highest PCE for p‐Si‐based solar cells using solution method. The findings provide a simple and promising method to achieve high‐performance PEDOT:PSS/p‐Si/ZnO HHSCs.