First-Principles and Experimental Insights into Interfacial Structures and Properties between MAPbI and ZnInX (X = S, Se).

The interface between the MAPbI perovskite and layered ZnInS was investigated by first-principles calculations combined with the experimental study. To begin with, four different types of interfacial configurations were established and carefully examined. The interaction occurring between MAPbI and ZnInX is mainly determined by weak van der Waals forces. The interfacial charge reorganization implies electron transfer from the MAPbI layer to the ZnInX layer across the interface. The PbI/ZnInX interface exhibits stronger interfacial interactions compared to those of the MAI/ZnInX counterpart. The interfacial adhesion work was found to depend more on the surface termination of MAPbI than on that of ZnInX. Conversely, it was discovered that the interface potential drop, work function, and dielectric function within the MAPbI/ZnInX interfaces are predominantly regulated by ZnInX termination rather than MAPbI termination. Chalcogen vacancies cause enhanced interfacial interactions owing to electron rearrangements at the interfaces. In the end, the MAPbI/ZnInS heterostructure was successfully fabricated and then characterized, which effectively verified first-principles calculations. This study offers fundamental insights into the development of MAPbI/ZnInX heterostructures, advancing perovskite-based optoelectronic devices.