In‐Situ Hydrogenation Strategies on Vanadium Oxide Hole‐Selective Contact for Efficiency Crystalline Silicon Solar Cells

Abstract Surface passivation and contact resistance are two main parameters to optimize the photoelectric performance of crystalline silicon/transition metal oxides (c‐Si/TMO) heterojunction solar cells. However, most studies focus on the introduction of dielectric layers at the heterojunction interface to improve the passivating contact performance, with limited attention given to optimizing the TMO film for improved photoelectric performance. Herein, an in‐situ hydrogen plasma treatment (HPT) process is employed to modulate the photoelectric properties of vanadium oxide (V ₂ O _x ) film as well as the c‐Si/V ₂ O _x interface. With increased O vacancy density in V ₂ O _x film and increased H bonds at c‐Si/V ₂ O _x interface, this c‐Si/HPT‐V ₂ O _x contact shows reduced contact resistivity and improved passivation properties. A satisfied power conversion efficiency (PCE) of close to 23% is achieved on p ‐type c‐Si solar cells with full area HPT‐V ₂ O _x rear hole selective contacts. The results show the high potential of V ₂ O _x as thermal and environmental stable hole selective contact for photovoltaic applications.