Valence band offset of ZnO∕4H-SiC heterojunction measured by x-ray photoelectron spectroscopy

The valence band offset (VBO) of the wurtzite ZnO∕4H-SiC heterojunction is directly determined to be 1.61±0.23eV by x-ray photoelectron spectroscopy. The conduction band offset is deduced to be 1.50±0.23eV from the known VBO value, which indicates a type-II band alignment for this heterojunction. The experimental VBO value is confirmed and in good agreement with the calculated value based on the transitive property of heterojunctions between ZnO, SiC, and GaN.