First-principles theory of metal-alkaline earth oxide interfaces

Abstract

Using calculations from first principles, we discuss the interplay between structure and functionality at metal-insulator interfaces using the paradigmatic example of the junctions between various metals (Ag, Pd, Pt, Ni, Cu, Al) and binary alkaline earth crystalline oxides ($\mathrm{BaO}$, $\mathrm{CaO}$, and $\mathrm{SrO}$). Our results demonstrate that it is possible to tune the Schottky barrier height in a very broad range of values by manipulating the metal at the interface, and elucidate the role of the relative overlap in the density of states of the different components in determining the band alignment. We conclude by stating a ``modified Schottky-Mott rule'' for this class of metal-insulator heterojunctions.