XPS is an important characterization method for epitaxial films and heterostructures. Although standard approaches for XPS data collection and analysis provide useful information such as average composition and the presence of contaminants, more in-depth analyses provide information about the film structure, surface termination, built-in electric potentials, and band offsets. The high degree of structural order in these materials enables such information to be extracted from spectral data but also adds complications to the analysis. This guide highlights three topics of importance in this field: (i) the impacts of crystallinity on XPS signals and quantification, (ii) the unexpected spectral line shapes that can occur in unusual or novel materials, and (iii) the ability of XPS to yield information about built-in potentials and band offsets. Concepts are demonstrated using complex oxide heterostructures. Although these topics are highly relevant to epitaxial films and heterostructures, they also apply to single crystals of complex materials.

中文翻译：

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XPS在外延膜和异质结构中应用的入门指南

XPS是外延膜和异质结构的重要表征方法。尽管用于XPS数据收集和分析的标准方法提供了有用的信息，例如平均成分和污染物的存在，但更深入的分析提供了有关膜结构，表面终止，内在电势和能带偏移的信息。这些材料的高度结构有序性使得可以从光谱数据中提取此类信息，但也增加了分析的复杂性。本指南重点介绍了该领域中的三个重要主题：（i）结晶度对XPS信号和定量的影响；（ii）在不寻常或新颖的材料中可能发生的意外光谱线形状；以及（iii）XPS的能力产生有关内置电势和带偏移的信息。使用复杂的氧化物异质结构演示了概念。尽管这些主题与外延膜和异质结构高度相关，但它们也适用于复杂材料的单晶。