Valence band offset of MgO/4H-SiC heterojunction measured by x-ray photoelectron spectroscopy

Abstract

The valence band offset (VBO) of MgO(111)/4H-SiC heterojunction has been directly measured by x-ray photoelectron spectroscopy. The VBO is determined to be 3.65±0.23 eV and the conduction band offset is deduced to be 0.92±0.23 eV, indicating that the heterojunction has a type-I band alignment. The accurate determination of the valence and conduction band offsets is important for the applications of MgO/SiC optoelectronic devices.