Abstract
Abstract
The band offsets of heterojunctions formed between indium tin oxide (ITO) and amorphous gallium oxide (a-GaO
x
) of different stoichiometric ratios were measured by x-ray photoelectron spectroscopy using the Kraut method. a-GaO
x
films with different stoichiometric ratios were deposited on commercial ITO/quartz substrates using radio frequency magnetron sputtering by varying the Ar/O2 flux ratio. With the increase of oxygen flux in the reaction gas, the oxygen vacancy (VO) concentration of a-GaO
x
decreases and its bandgap increases from 5.2 eV to 5.32 eV, while the valence band offset of ITO/a-GaO
x
heterojunction changes from 0.29 ± 0.07 eV to −0.74 ± 0.06 eV and conduction band offset changes from 0.95 ± 0.085 to 2.10 ± 0.075 eV. The results indicate that the band alignment of ITO/a-GaO
x
heterojunction can change from type I to type II with the variation of Ga/O stoichiometric ratio, which can provide guidance for the design of their corresponding high-performance heterostructured devices.
Funder
Sichuan Province Science and Technology Program
Cooperation project of Sichuan University-Jiangsu Pangea Semiconductor Equipment Technology Co., Ltd
Sichuan Demonstration Project of Transfer and Transformation of Scientific and Technological Achievements
Subject
Surfaces, Coatings and Films,Acoustics and Ultrasonics,Condensed Matter Physics,Electronic, Optical and Magnetic Materials