First Principle Hybrid Density Functional Theory Study of Halide Perovskite Surfaces and Interfaces

Perovskite materials continue to revolutionize multiple optoelectronic fields with applications in solar cells, light emitting diodes, photodetectors and lasers. High quality devices are developed with low-cost precursors at room temperature using solution processing. Computational studies have been used to predict new perovskites and transport layer interfaces as well as describe the photophysics of already-made devices so perovskite-based technologies can reach their full potential. We show here hybrid density functional theory calculation on the interface between an inorganic perovskite (CsPbBr$_{\mathrm{3}})$ and inorganic hole transport layer (CuI). Band offset calculations between CsPbBr$_{\mathrm{3\thinspace }}$and CuI reveal the tunability of the interface offset potential through varied material thickness, where the offset converges for structures over nine-unit cells thick. Experiments have recently been published showing the viability of CuI as a hole transport layer in perovskite-based devices.