Funding information Swiss National Science Foundation, Grant/ Award Number: 206021_182987 The greater information depth provided in hard X-ray photoelectron spectroscopy (HAXPES) enables nondestructive analyses of the chemistry and electronic structure of buried interfaces. Moreover, for industrially relevant elements like Al, Si, and Ti, the combined access to the Al 1s, Si 1s, or Ti 1s photoelectron line and its associated Al KLL, Si KLL, or Ti KLL Auger transition, as required for local chemical state analysis on the basis of the Auger parameter, is only possible with hard X-rays. Until now, such photoemission studies were only possible at synchrotron facilities. Recently, however, the first commercial XPS/HAXPES systems, equipped with both soft and hard X-ray sources, have entered the market, providing unique opportunities for monitoring the local chemical state of all constituent ions in functional oxides at different probing depths, in a routine laboratory environment. Bulk-sensitive shallow core levels can be excited using either the hard or soft X-ray source, whereas more surface-sensitive deep core-level photoelectron lines and associated Auger transitions can be measured using the hard X-ray source. As demonstrated for thin Al2O3, SiO2, and TiO2 films, the local chemical state of the constituting ions in the oxide may even be probed at near-constant probing depth by careful selection of sets of photoelectron and Auger lines, as excited with the combined soft and hard X-ray sources. We highlight the potential of lab-based HAXPES for the research on functional oxides and also discuss relevant technical details regarding the calibration of the kinetic binding energy scale.

中文翻译：

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基于实验室的 XPS/HAXPES 结合软硬 X 射线源在恒定探测深度进行化学状态分析的概念

资金信息 瑞士国家科学基金会，资助/奖励编号：206021_182987 硬 X 射线光电子能谱 (HAXPES) 提供的更大信息深度能够对埋入界面的化学和电子结构进行无损分析。此外，对于 Al、Si 和 Ti 等工业相关元素，根据局部化学反应的需要，结合使用 Al 1s、Si 1s 或 Ti 1s 光电子线及其相关的 Al KLL、Si KLL 或 Ti KLL 俄歇跃迁基于俄歇参数的状态分析只能用硬 X 射线进行。到目前为止，这种光发射研究只能在同步加速器设施中进行。然而，最近，第一批配备软和硬 X 射线源的商用 XPS/HAXPES 系统已经进入市场，为在常规实验室环境中监测不同探测深度的功能性氧化物中所有成分离子的局部化学状态提供了独特的机会。体敏感的浅核能级可以使用硬 X 射线源或软 X 射线源激发，而更表面敏感的深核能级光电子线和相关的俄歇跃迁可以使用硬 X 射线源进行测量。正如薄的 Al2O3、SiO2 和 TiO2 薄膜所证明的那样，通过仔细选择光电子和俄歇线组，甚至可以在接近恒定的探测深度探测氧化物中构成离子的局部化学状态，如被组合软和硬 X 射线源。