The donor-dependent methoxy effects on the performance of hole-transporting materials for perovskite solar cells

Abstract In this work, a comprehensive study on the deliberate molecular design and modifications of electron donors is carried out to elucidate correlations between the methoxy effects and donor configuration of hole-transporting materials (HTMs). Our initial findings demonstrate the donor-dependent methoxy effects. Photovoltaic performance of the HTM with twisted donor highly depends on the methoxy substituent. In contrast, efficiency's reliance on methoxy is insignificant for the HTM with planar donor. The HTM (M123) featuring the methoxy-substituted carbazole shows a decent power conversion efficiency of 19.33% due to synergistic effects from both planar structure and methoxy. This work gives a guideline to access HTMs reaching both high-performance and good stability.