Corannulene-based hole-transporting material for efficient and stable perovskite solar cells
Mingwei An, Baoshan Wu, Shun Wang, Zuo‐Chang Chen, Yin Su, Lin‐Long Deng, Shu‐Hui Li, Zi‐Ang Nan, Han‐Rui Tian, Xiaolin Liu, Daqin Yun, Qianyan Zhang, Su‐Yuan Xie, Lan‐Sun Zheng
Abstract
Core structures with linear, planar, and spiral conformations have been designed as triphenylamine (TPA)-based hole-transporting materials (HTMs), which are the most prevalent small molecular HTMs in perovskite solar cells (PSCs). However, most of the reported TPA-based HTMs cannot achieve sufficient balance between efficiency and stability, which is governed by core structures. Herein, a sym -penta( N,N -bis(4-methoxyphenyl)aniline)corannulene (cor-OMePTPA) featuring a corannulene core and five TPA peripheral arms is designed as alternative HTM. Planar negative-intrinsic-positive (n-i-p) PSCs with cor-OMePTPA exhibit champion efficiencies of 20% and maintain 86% of their initial performances for more than 1,000 h after thermal annealing at 60°C. Compared with spiro-OMeTAD, cor-OMePTPA-based PSCs show slightly lower efficiencies but much better thermal stabilities. The main merit of cor-OMePTPA lies in its bimolecular interpenetration capability with noncovalent interactions to modulate the HTM configurations from single-molecular curvature to bimolecular planarity, thereby providing promising opportunities to achieve excellent balance between efficiency and stability.