Peak separation methods for inverse photoelectron spectra: Comparing second derivative, curve fitting, and deconvolution analyses

[Abstract] Inverse photoelectron spectroscopy (IPES) is a powerful technique for probing the unoccupied electronic states of 11 materials. It can be regarded as the inversion process of photoelectron spectroscopy (PES), which examines the 12 occupied states. Recently developed low-energy inverse photoelectron spectroscopy (LEIPS) can significantly 13 advance the study of unoccupied states, owing to minimal sample damage and suppressed dark counts compared to 14 conventional IPES. However, the instrumental resolution remains at 0.2 eV, which is one order of magnitude lower 15 than that of PES. Spectral broadening caused by the low instrumental resolution often results in overlapping peaks. 16 Peak separation is therefore crucial in the analysis of LEIPS spectra. In this study, we compared three peak separation 17 methods—second derivative, curve fitting, and deconvolution. These methods were applied to modeled and 18 experimental LEIPS spectra of the lowest unoccupied molecular orbital-derived band of pentacene, which consists 19 of two splitting peaks due to the two inequivalent molecules in the unit cell. We systematically and quantitatively 20 evaluated the performance of each method in terms of analysis parameters and discussed its robustness to noise as 21 well as its peak separation capabilities as a function of peak energy spacing and intensity ratio. This work offers a 22 practical framework for peak separation in LEIPS, with extensions to PES and a wide range of spectroscopies.

https://opac.ll.chiba-u.jp/da/curator/900123739/

https://opac.ll.chiba-u.jp/da/curator/900123739/RSI25-AR-01881.pdf

AIP Publishing

Journal Article

Review of Scientific Intruments

97

2

023906

2026-02-19

https://doi.org/10.1063/5.0303140

eng

https://doi.org/10.1063/5.0303140

author

This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in Review of Scientific Instruments 97, 023906 (2026) and may be found at https://doi.org/10.1063/5.0303140 .