Partial secondary electron-yield NEXAFS spectromicroscopy with an energy-filtered X-PEEM

The narrow energy band pass of an energy-filtered x-ray photoemission electron microscope (X-PEEM) can lead to unusual artifacts when used for spatially resolved near-edge x-ray absorption fine structure (NEXAFS) spectroscopy and imaging of organic surfaces. Work-function differences and the rapid work-function change with radiation exposure can impair quantitative chemical analysis by NEXAFS and invert the expected image contrast. We also find that "partial-yield" detection from the narrow energy band pass of an energy-filtered X-PEEM can lead to distorted NEXAFS spectra. These observations not only are relevant for the analysis of organic surfaces by energy-filtered X-PEEM but also call into question some assumptions about quantitative NEXAFS spectroscopy.