Small valence-band offset of In_(0.17)Al_(0.83)N/GaN heterostructure grown by metal-organic vapor phase epitaxy

摘要

The valence-band offset of a lattice-matched In_(0.17)Al_(0.83)N/GaN heterostructure grown by metal-organic vapor phase epitaxy (MOVPE) was investigated by x-ray photoelectron spectroscopy (XPS). Atomic force microscopy and angle-resolved XPS indicated that a thin In_(0.17)Al_(0.83)N (2.5 nm) layer was successfully grown by MOVPE on GaN. The XPS result showed that the valence band offset was 0.2 ±0.3 eV. This result indicates that the conduction-band offset at the In_(0.17)Al_(0.83)N/GaN interface is large, i.e., 0.9 to 1.0 eV, and occupies a large part of the entire band discontinuity.