Journal Article

UV-Engineered Oxygen Vacancies in MoO X Interlayers Enable 24.15% Efficiency for Crystalline Silicon Solar Cells

Zhu, Ji, Liu, Tinghao, Wang, Yin, Yan, Hui, Li, Jingjie, Zhang, Yongzhe, Kang, Qian, Lu, Wanyu, Chen, Shaopeng, Yuan, Dayong, Yang, Linfeng

2025

Overview

Molybdenum oxide (MoO ) has been widely utilized as a hole transport layer (HTL) in crystalline silicon ( -Si) solar cells, owing to characteristics such as a wide bandgap and high work function. However, the relatively low conductivity of MoO films and their poor contact performance at the MoO -based hole-selective contact severely degrade device performance, particularly because they limit the fill factor (FF). Oxygen vacancies are of paramount importance in governing the conductivity of MoO films. In this work, MoO films were modified through ultraviolet irradiation (UV-MoO ), resulting in MoO films with tunable oxygen vacancies. Compared to untreated MoO films, UV-MoO films contain a higher density of oxygen vacancies, leading to an enhancement in conductivity (2.124 × 10 S/m). In addition, the UV-MoO rear contact exhibits excellent contact performance, with a contact resistance of 20.61 mΩ·cm , which is significantly lower than that of the untreated device. Consequently, the application of UV-MoO enables outstanding hole selectivity. The power conversion efficiency (PCE) of the solar cell with an n-Si/i-a-Si:H/UV-MoO /Ag rear contact reaches 24.15%, with an excellent FF of 84.82%.