Essential Principles and Practices in X-ray Photoelectron Spectroscopy

Abstract: X-ray Photoelectron Spectroscopy (XPS) is a widely utilized technique for chemical analysis of solid surfaces, sensitive to the chemical environment of atoms via core-level binding energy shifts. While modern instruments allow obtaining the experimental data with ease, their evaluation and interpretation is challenging to newcomers to the field as a profound knowledge of the method is required for a correct analysis. Here we present a concise yet comprehensive introduction to the fundamental principles and methodologies of XPS, covering photoemission processes, chemical shifts, charge referencing, peak fitting, and quantification strategies. This overview aims to bridge the gap between data collection and reliable analysis, providing essential knowledge for correct interpretation. By clarifying key concepts and common practices, this work supports improved accuracy in surface chemical characterization using XPS.