Superior Intermolecular Noncovalent Interactions Empowered Dopant‐Free Hole Transport Materials for Efficient and Stable Sb<sub>2</sub>(S,Se)<sub>3</sub> Solar Cells
Wangchao Chen, Miaomiao Wu, Xuan Chen, Zhi Zhang, Fuling Guo, Hong Zhang, Yanqing Wang, Gang Ni, Ling Qin, Chengwu Shi
Abstract
Abstract Antimony selenosulfide (Sb 2 (S,Se) 3 ) solar cells are critically restrained by the Sb 2 (S,Se) 3 /charge transport layer interface with scarce carriers transfer ability and high density of deep‐level defect‐induced traps, which are prone to spark the nonradiative recombination and capture the benign photogenerated carriers. Herein, utilizing the intermolecular noncovalent interactions strategy in molecular stereoscopic structural engineering, two dopant‐free hole transport materials (HTMs) are constructed, coded as T‐BDT and F‐BDT, with synergistic hole selectivity and interfacial healing ability. The theoretical simulation and experimental results decipher that the F‐BDT possesses the more favorable planarized conformation, charge delocalization/coupling and molecular stacking pattern, which endow it with the salient hole selection, robust interface passivation and appropriate energy level alignment. Consequently, the Sb 2 (S,Se) 3 solar cell with F‐BDT as dopant‐free HTM realize an outstanding power conversion efficiency of 9.13%, hitting the record high for Sb 2 (S,Se) 3 devices under dopant‐free conditions.