Photoemission Spectroscopy: Photoemission Spectroscopy Characterization of Halide Perovskites (Adv. Energy Mater. 26/2020)

The cover image for article number 1904007, Solène Béchu, Philip Schulz and co-workers represents the principle of photoemission spectroscopy, applied to perovskite materials. The background is a modified picture of a spectrometer taken by one of the authors. After photoexcitation, electrons from the perovskite are ejected and travel through an analyzer which then provides a spectrum with chemical information about the elements present in the perovskite. Further information can be gained from the analysis of the resulting spectra: the atomic composition, the oxidation levels of elements, and also the electronic properties.