Band alignment of p-type oxide/e-Ga2O3 heterojunctions investigated by x-ray photoelectron spectroscopy

• 作者: Chang Rao Gang Wang Jun Liang Weiqu Chen Xing Lu Xinzhong Wang Yanli Pei Zeyuan Fei Zimin Chen
• 来源期刊: 中国物理B（英文版）
• 年，卷（期）: 2020,（9）
• 所属期刊栏目: CONDENSED MATTER: ELECTRONIC STRUCTURE, ELECTRICAL, MAGNETIC, AND OPTICAL PROPERTIES
• 页码范围: 534-540
• 页数: 7页
• 语种: 英文
• DOI: 10.1088/1674-1056/ab9c0d

摘要

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.