Understanding and Controlling the Work Function of Perovskite Oxides Using Density Functional Theory

Perovskite oxides containing transition metals are promising materials in a wide range of electronic and electrochemical applications. However, neither their work function values nor an understanding of their work function physics have been established. Here, the work function trends of a series of perovskite (ABO 3 formula) materials using density functional theory are predicted, and show that the work functions of (001)‐terminated AO‐ and BO 2 ‐oriented surfaces can be described using concepts of electronic band filling, bond hybridization, and surface dipoles. The calculated range of AO (BO 2 ) work functions are 1.60–3.57 eV (2.99–6.87 eV). An approximately linear correlation ( R 2 between 0.77 and 0.86 is found, depending on surface termination) between work function and position of the oxygen 2 p band center, which correlation enables both understanding and rapid prediction of work function trends. Furthermore, SrVO 3 is identified as a stable, low work function, highly conductive material. Undoped (Ba‐doped) SrVO 3 has an intrinsically low AO‐terminated work function of 1.86 eV (1.07 eV). These properties make SrVO 3 a promising candidate material for a new electron emission cathode for application in high power microwave devices, and as a potential electron emissive material for thermionic energy conversion technologies.