Adhesion in Perovskite Solar Cell Multilayer Structures

It is important to understand the interfacial robustness of promising multilayer structures of perovskite solar cells (PSCs) due to their weak adhesion at interfaces, which can lead to failure or delamination in the structures. Herein, we used force microscopy to quantify the adhesive interactions between adjacent layers of PSCs. The measured pull-off forces are elucidated to rank the adhesion interaction between layers of PSCs that are deposited by vapor and solution crystallization. The effects of crystallized conditions on perovskite morphologies are also studied. The interfacial adhesive forces are then correlated to device performances and charge transfer resistances between perovskites and charge transport layers. The results found that high adhesion forces within solution-processed PSCs led to the low resistance of charge carrier transport across the devices and improved photoconversion efficiencies. The implications of the results are then discussed for the design of robust PSCs.