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The ε-Ga2O3 p-n heterojunctions (HJ) have been demonstrated using typical p-type oxide semiconductors (NiO or SnO).The ε-Ga2O3 thin film was heteroepitaxial grown by metal organic chemical vapor deposition (MOCVD) with threestep growth method.The polycrystalline SnO and NiO thin films were deposited on the ε-Ga2O3 thin film by electron-beam evaporation and thermal oxidation,respectively.The valence band offsets (VBO) were determined by x-ray photoelectron spectroscopy (XPS) to be 2.17 eV at SnO/ε-Ga2O3 and 1.7 eV at NiO/ε-GaaO3.Considering the bandgaps determined by ultraviolet-visible spectroscopy,the conduction band offsets (CBO) of 0.11 eV at SnO/ε-Ga2O3 and 0.44 eV at NiO/ε-Ga2O3 were obtained.The type-Ⅱ band diagrams have been drawn for both p-n HJs.The results are useful to understand the electronic structures at the ε-Ga2O3 p-n HJ interface,and design optoelectronic devices based on ε-Ga2O3 with novel functionality and improved performance.