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.

中文翻译：

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X射线光电子能谱研究GaN/CH3NH3PbBr3异质结能带排列

通过等离子体增强原子层沉积在 CH3NH3PbBr3 单晶上沉积 GaN 薄层来制造 GaN/CH3NH3PbBr3 异质结。通过 X 射线光电子能谱研究了 GaN/CH3NH3PbBr3 异质结的能带排列。价带偏移 (VBO) 直接确定为 0.13 ± 0.08 eV。从 VBO 和带隙推导出导带偏移，结果为 1.39 ± 0.12 eV。因此，GaN/CH3NH3PbBr3异质结的能带排列被确定为I型。这些结果表明，GaN 是一种很有前途的材料，可用于卤化物钙钛矿基发光器件中的载流子限制。