Abstract
Photocathode is a critical component in applications such as electron source, photomultipliers and image intensifiers. The harsh operation conditions put forward multiple requirements of current photocathode materials (i.e., GaAs, GaN, K2CsSb). Meanwhile, Halide perovskites have been reported with plenty of fantastic properties and are expected as a potential candidate for photocathode. In this study, we use first-principle calculations to investigate the feasibility of application of CsPbBr3 as photocathode. The surface coatings of Cs adatoms with different coverages is explored. The dynamic evolution of the adsorption process suggests a saturated coverage of 6/8 ML for in-plane coating. Based on the theoretical framework of electron density and polarization density, a direct link between reduction of work function and dipole moment is established. The minimum work function of functionalized (001) surface attains at 1.05 eV with Cs coverage of 6/8 ML. Significant band bending on the surface after Cs incorporation is observed according to the analysis of band structure and layer-by-layer density of states. The results of this work aim to guide further experimental development of the Cs activated process for broader families of halide perovskites as photocathode materials.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have