Study on the band alignment of GaN/CH3NH3PbBr3 heterojunction by x-ray photoelectron spectroscopy

• Published in: Applied physics letters Vol. 111; no. 12
• Main Authors: Gong, Jinhui, Liu, Shitao, He, Yuandan, Feng, Xingcan, Xia, Xuefeng, Quan, Zhijue, Wang, Li
• Format: Journal Article
• Language: English
• Published: Melville American Institute of Physics 18-09-2017
• Subjects: Alignment; Applied physics; Atomic layer epitaxy; Conduction bands; Crystals; Electrons; Heterojunctions; Perovskites; Photoelectron spectroscopy; Single crystals; Spectrum analysis; X ray photoelectron spectroscopy
• ISSN: 0003-6951; 1077-3118
• DOI: 10.1063/1.4997229

A GaN/CH3NH3PbBr3 heterojunction was fabricated by depositing a GaN thin layer on a CH3NH3PbBr3 single crystal by plasma enhanced atomic layer deposition. The band alignment of the GaN/CH3NH3PbBr3 heterojunction was studied by x-ray photoelectron spectroscopy. The valance band offset (VBO) is directly determined to be 0.13 ± 0.08 eV. The conduction band offset is deduced from the VBO and the band gaps, which turned out to be 1.39 ± 0.12 eV. Thus, the band alignment of the GaN/CH3NH3PbBr3 heterojunction is determined to be type-I. These results show that GaN is a promising material for carrier confinement in halide perovskite based light emitting devices.