Mechanically stable screen-printed flexible perovskite solar cells via selective self-assembled siloxane coupling agents
Meiru Duan, Jinxian Yang, Tai Li, Junlin Wen, Biyun Ren, Kaiyu Wang, Yingdong Xia, Hui Zhang, Yonghua Chen
Abstract
Owing to unique advantages of patternability and high substrate compatibility, screen-printing allows for the fabrication of flexible perovskite solar cells (f-PSCs) with designable device patterns, while the defective and fragile contact at the buried interface seriously restricted the device performance. Herein, a series of siloxane coupling agents (SCAs) with different ending groups i.e., –SH, –NH2, and –CN were incorporated at the SnO2/perovskite interface, which can selectively interact with MA+ and Pb2+ via hydrogen and coordination bonding, respectively. It was revealed that the selection of (3-Cyanopropyl)Triethoxysilane (CN-PTES) can regulate perovskite crystallization with accelerated nucleation and retarded crystal growth, leading to improved crystallinity with released residual lattice strain. Moreover, the incorporated CN-PTES aligned the energy structure of the underlying SnO2 and boosted the interfacial adhesion between perovskite and SnO2, resulting in facilitated electron extraction and enhanced interfacial fracture energy. Consequently, the first screen-printed f-PSCs with improved mechanical resistance were finally obtained.