Measurement of Semi-Polar (11–22) Plane AlN/GaN Heterojunction Band Offsets by X-ray Photoelectron Spectroscopy

The valence band offset (VBO) of the semi-polar (11–22) plane AlN/GaN heterojunction has been directly measured by X-ray photoelectron spectroscopy. The VBO is determined to be 0.7 ± 0.2 eV and the conduction band offset is deduced to be 2.1 ± 0.2 eV. The VBO of semi-polar AlN/GaN heterojunctions is smaller than the C-plane AlN/GaN heterojunctions due to the polarization effects partially eliminated.