XPS analysis of <i>in situ</i> exfoliated zirconium diselenide (ZrSe2) single crystal

A two-dimensional single crystal of the transition metal dichalcogenide, zirconium diselenide (ZrSe2), was exfoliated in situ and analyzed by x-ray photoelectron spectroscopy (XPS). Survey scan and high-resolution spectra of Zr 3d, Se 3p, Se 3d, Se LMM, Zr 4s, O 1s, Zr 3p, Zr 4p, O 2s, Se 3s, Zr 3s, Se 4s, C 1s, and the valence band were obtained following exfoliation under ultrahigh vacuum (UHV) conditions. Both Zr and Se core levels were found to exist in a single chemical state, corresponding to ZrSe2. Severe overlap between photoelectron peaks and Se Auger peaks, notably in the case of Zr 3d and C 1s core levels, presents a major challenge for precise XPS peak assignment and quantification. The work includes recommendations to deal with Auger interference with the Zr 3d doublet.