Engineering of dendritic dopant-free hole transport molecules: enabling ultrahigh fill factor in perovskite solar cells with optimized dendron construction

Wei Chen, Yang Wang, Bin Liu, Yajun Gao, Ziang Wu, Yongqiang Shi, Yumin Tang, Kun Yang, Yujie Zhang, Weipeng Sun, Xiyuan Feng, Frédéric Laquai, Han Young Woo, Aleksandra B. Djurišić, Xugang Guo, Zhubing He