Band offsets in sputtered Sc2O3/InGaZnO4 heterojunctions

We measured the band offsets of sputtered Sc2O3 on thin film InGaZnO4 (IGZO) using X-Ray Photoelectron Spectroscopy and obtained the bandgaps of the materials using reflection electron energy loss spectroscopy and UV/Vis absorption. The valence band offset was determined to be −1.33 eV ± 0.13 eV for Sc2O3 on sputtered IGZO (bandgap 3.16 eV). The conduction band offset for Sc2O3/IGZO was then determined to be 4.07 eV. The Sc2O3/IGZO system has a staggered, type II alignment, meaning that it is not suitable for thin film transistors but it may still be useful for surface passivation to prevent the commonly observed changes in conductivity of the IGZO resulting from atmospheric exposure.