Evolving efforts to maintain and improve XPS analysis quality in an era of increasingly diverse uses and users

Abstract

Based on literature analysis, X-ray photoelectron spectroscopy (XPS) use continues to increase exponentially. This increased use is accompanied by anecdotal reports and systematic analyses indicating a growing presence of significantly flawed data analyses. Recognition of this problem within the surface analysis community has increased with an understanding that both inexperienced users and increased use of XPS outside the surface analysis community contribute to the problem. The XPS community has initiated several efforts to help address the problem, which is not unique to XPS. This paper describes some of the specific problems identified and some of the community efforts intended to address them. Here, we describe activities focused on three specific issues: (i) requests for detailed guides and protocols and bite-sized versions of information for non-experts, (ii) incomplete data and analysis reporting, and (iii) the high rate of peak fitting problems. A 2019 survey identified the need for guides, protocols, and standards to assist XPS users. One set of such guides has been published, and another is being assembled. Providing incremental bites of useful information is the goal of a series of papers on specific challenges to surface analysis with example solutions has been initiated as Notes and Insights papers in Surface and Interface Analysis. Examination of XPS-containing papers finds that information to establish the credibility and reproducibility of XPS results is often very incomplete.Unfortunately, ISO and ASTM standards require an amount of parameter reporting that seems excessive and unrealistic for many research publications. Initial approaches to develop and distribute a graded approach to parameter reporting are briefly described. Multiple efforts are underway to address the high rate of problems associated with photoelectron peak fitting. These include guides to peak fitting, guides to peak identification and fitting for specific elements, and the development of a peak fitting social network. The fitting social network is designed to facilitate interactions between new and experienced XPS users; analysts trying to fit XPS data (for publication or other reasons) can ask questions and establish dynamic conversations. Encouraging and enabling high-quality XPS analysis and reporting requires several different types of effort from all members of the surface and interface analysis community.

Photoelectron spectroscopy of ceria: Reduction, quantification and the myth of the vacancy peak in XPS analysis

“…There has been a recent drive to address the so‐called reproducibility crisis in x‐ray photoelectron spectroscopy (XPS) 1–3 with focused topics such as the use of correct standards and terminology, 4,5 peak fitting and data analysis 6–9 and sample handling 10 to name but a few. While these papers are a must‐read for any practitioner of XPS, for novice users, there can still be a barrier to question quantified data which can lead to the propagation of errors in the literature.…”

Surface analysis insight note. Principal component analysis (PCA) of an X‐ray photoelectron spectroscopy image. The importance of preprocessing

“…In response to this, a series of guides on XPS was recently written in the Journal of Vacuum Science and Technology 16–25 . The Insight Notes in Surface and Interface Analysis are also a response to this problem 26 …”

“…[16][17][18][19][20][21][22][23][24][25] The Insight Notes in Surface and Interface Analysis are also a response to this problem. 26 With increasing advances in vacuum components, software, and instrumentation, XPS has become a precise and powerful technique that is now available in multiple modes. These variants now include near ambient pressure, 27 operando, 28,29 angle-resolved, HAXPES (XPS with high-energy X-rays), 30 depth profiling, 19,20 which is increasingly performed with gas cluster ion beams (GCIBs), 31 and imaging.…”

Surface analysis insight note: Analysis of X‐ray photoelectron spectroscopy images with summary statistics

“…In response to this concern, guides that cover multiple aspects of the technique have recently been written 1,3,5,8–14 . Another recent effort to provide high‐quality tutorial information to XPS users is the Insight Notes in Surface and Interface Analysis 15 . This article is one of these Notes.…”

“…1,3,5,[8][9][10][11][12][13][14] Another recent effort to provide highquality tutorial information to XPS users is the Insight Notes in Surface and Interface Analysis. 15 This article is one of these Notes.…”