Band offsets in ZrO₂/InGaZnO₄ heterojunction

Abstract

X-ray photoelectron spectroscopy was used to measure the energy discontinuity in the valence band (△EV) of amorphous InGaZnO4 (a-IGZO)/ZrO2 heterostructure deposited by DC and RF sputtering at room temperature, respectively. A value of △EV = 0 eV was obtained by using the Ga and Zn 2p3 and In 3d3 energy levels as references. Given the experimental band gap of 3.1 eV and 5.8 eV for the a-IGZO and ZrO2, respectively, this would indicate a conduction band offset of 2.7 eV in the system.