Energy-band alignments at ZnO/Ga2O3 and Ta2O5/Ga2O3 heterointerfaces by X-ray photoelectron spectroscopy and electron affinity rule

摘要

Wide bandgap oxide semiconductors have been a hot topic in electronic and optoelectronic technologies. The oxide heterojunctions provide many significant favorable properties in devices. The energy-band alignments at the heterointerfaces between oxides play a key role in the functional electronics. In this work, we studied the band alignments of ZnO/Ga2O3 and Ta2O5/Ga2O3 heterojunctions. The valence band offsets of Ta2O5/Ga2O3 and ZnO/Ga2O3 heterojunctions were determined by X-ray photoelectron spectroscopy. The Ta2O5/Ga2O3 heterojunction exhibits a type II band alignment with a valence band offset of