The XPS Library  

The XPS Library is a Not-for-Profit institute that offers graduate students, post-docs, professors, engineers, scientists, and managers an extensive library of XPS spectra, information, explanations, definitions, guidance, charts, examples of overlays, and key insights into the many facets of XPS.

The complete collection of >70,000 Monochromatic XPS Spectra are available with software, Spectra Data Processor, SDP v8.0, and 7 PDF books at no charge to registered members , but you must register to download any spectra, PDF books, or the SDP v8 software.

The XPS Library asks group leaders to donate $50 per year to help maintain this website.  This site focuses on the use of graphic information and graphic guidelines to assist all XPS scientists to collect and process their in-house monochromatic XPS spectra.  The use of info-graphics with written content is meant to assist learning by beginners. Because this site is new, there are many sections that can be improved.  Suggestions are welcome.  If you wish to assist the development of this site, then please become a contributor.  We currently have several known experts providing detailed explanations to support the graphic plots, charts, spectra and tables you find here.

Our Mission is Two Fold

Part One

The main function of The XPS Library is to assist graduate students, professors, XPS tool owners, XPS instrument users, journal editors, and journal reviewers in their efforts to make and provide “reliable” chemical state assignments in all journal publications and databases of BEs.

To make this happen, The XPS Library is maintaining a image-based database that stores the “screen grabs – print screen” images of the actual peak-fitted Au, Ag or Cu calibration spectra that are used to check the Calibration BEs of each registered XPS instrument.  These “screen-grabs – print screen” copies of the actual spectra must be recorded and submitted monthly for each instrument.

These image based records will help everyone to understand the usefulness and reliability of the experimental research BEs that are published in many journals around the world.   The measured calibration BEs will be stored in an on-line database open to all Registered Members, journal editors, and publication reviewers around the world.  These “measured calibration BEs” will allow all users to make any necessary adjustments in published BEs to better understand and interpret their in-house research BEs, and to make more accurate and more reliable chemical state assignments.

Part Two

The second function of The XPS Library is to assist XPS users who must identify the chemical states that exist in high energy resolution XPS spectra.  The “Peak-fitting” task looks easy, but is actually quite challenging if you want to generate reliable and accurate “Peak-fits” (aka curve-fits), and be able to correctly assign the chemical state that belongs to each individual peak-signal resolved in the peak-fit (curve-fit).

To achieve this goal, expert contributors have provided explanations and examples of “good” peak-fits and also “bad” peak-fits. Expert contributors will also provide useful examples of  “chemical state assignments” to peak-fitted results.  The expert contributors base their chemical state assignments on many tens of years of experience, and also on cross-correlation between the “atom%” values for each element and the atom% values due to each peak-fit signal.  These chemical state assignments can be very difficult to make because the surface of many materials, even so-called “pure” materials, can have gradients or islands within the depth of information (1-12 nm) provided by XPS analyses.


Not-For-Profit Institute

“The XPS Library” is a not-for-profit institute that operates in the state of Oregon using several web domain names to route users to our website.  Our re-routing website addresses are:



The XPS Library is dedicated to the Memory of Professor Kai Siegbahn and Charles D. Wagner, and the efforts of Uppsala University and Lehigh University.

Professor Kai Siegbahn   




Charles D. Wagner,  the source of the BEs in the NIST Database 





The Scientists who made XPS Possible



The Optical Phenomenon that produces the Photoelectric Effect




The Wide Range of Applications of XPS





The Almost Exponential Rise in XPS Publications starting in 1985