Searching for Low Work Function Perovskite Oxides using Density Functional Theory

Abstract

The work function is a crucial parameter for electron emitters used in vacuum electronic devices as lower function allows higher current density and/or lower operating temperature. Perovskite oxides are a novel class of materials for potential use in electron emission applications due to their tunable work functions, robust stability, and good electronic conductivity. In this work, we performed a high-throughput screening based on Density Functional Theory (DFT) simulations and predicted BaMoO 3 to be promising emitter materials with low work function, good stability and high electronic conductivity. Our work also provides a general materials design principle governing the work function of perovskites, which is that perovskites with nearly empty electronic d-bands have the lowest work functions.