InN/GaN valence band offset: High-resolution x-ray photoemission spectroscopy measurements

High-resolution x-ray photoemission spectroscopy measurements are used to determine the valence band offset of wurtzite-InN/GaN(0001) heterojunctions to be 0.58 +/- 0.08 eV. This is discussed within the context of previous measurements and calculations and is in agreement with the value of 0.52 +/- 0.14 eV determined from the alignment of the experimentally determined charge neutrality levels in InN and GaN. The heterojunction forms in the type-I straddling configuration with a conduction band offset of 2.22 +/- 0.10 eV.