Abstract Energy band lineup at hetero-interface and its physical origin have been always a fascinating issue, and are being intensely investigated. The understanding of the influence of an interlayer on the band lineup of hetero-interface provides a view of studying the band lineup of hetero-interface. Thus in this paper, the Al2O3/GeOx/Ge structure is employed, and the effect of interlayer GeOx thickness on band lineup of Al2O3/GeOx/Ge structure is studied by X-ray photoelectron spectroscopy technique. The valence band offset of Al2O3/Ge hetero-interface is found to be nearly identical (3.5 eV) for different GeOx thicknesses (0.2 nm ~ 1.2 nm). The gap states model is employed to successfully explain these results. The interfacial dipole in Al2O3/GeOx/Ge structure is nearly unchanged with GeOx thickness based on the gap states model. This indicates that the band lineup of Al2O3/GeOx/Ge structure is independent on GeOx thickness. Thus these further verify that the gap state model is feasible in elucidating energy band lineup at hetero-interfaces.

中文翻译：

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层间GeOx厚度对Al2O3/GeOx/Ge结构能带排列的影响

摘要 异质界面的能带排列及其物理起源一直是一个引人入胜的问题，并受到广泛研究。理解夹层对异质接口能带排列的影响，为研究异质接口能带排列提供了一个视角。因此本文采用Al2O3/GeOx/Ge结构，利用X射线光电子能谱技术研究层间GeOx厚度对Al2O3/GeOx/Ge结构能带排列的影响。对于不同的 GeOx 厚度 (0.2 nm ~ 1.2 nm)，发现 Al2O3/Ge 异质界面的价带偏移几乎相同 (3.5 eV)。间隙状态模型被用来成功解释这些结果。基于间隙态模型，Al2O3/GeOx/Ge 结构中的界面偶极子几乎不随 GeOx 厚度变化。这表明 Al2O3/GeOx/Ge 结构的能带阵容与 GeOx 厚度无关。因此，这些进一步验证了间隙态模型在阐明异质界面的能带阵容方面是可行的。