Dopant-Free Hole-Transport Materials Based on 2,4,6-Triarylpyridine for Inverted Planar Perovskite Solar Cells
Liangsheng Duan, Yu Chen, Jingwen Jia, Xueping Zong, Zhe Sun, Quanping Wu, Song Xue
Abstract
New building blocks of cores and periphery groups for organic hole-transporting materials (HTMs) have been paid much attention for recent development in perovskite solar cells (PSCs). In this work, we applied facile synthesis to join a 2,4,6-triarylpyridine building block for new HTMs based on a pyridine core by cheap industrial initial materials. The three small molecules, namely, D104, D105, and D106, were used in the pristine state. To the best of our knowledge, pyridine-cored dopant-free HTMs have not been reported in PSCs. The changing periphery 4-methoxyphenyl and bis(4-methoxyphenyl)amine groups formed different Y-shapes. Under 1 sun conditions, the devices achieved an increased power conversion efficiency (PCE) of 16.28%, 17.40%, and 18.24% for D104, D105, and D106. They displayed great potential with improved stability in inverted planar PSCs. The unencapsulated device in ambient environment (30% RH) based on D104, D105, and D106 retained 33%, 70%, and 75% of the initial PCE after 275 h.