The Cu, In, and Se core-level electron binding energies of the p-type Cu–In–Se–N thin film were larger than those of the n-type Cu–In–Se thin film. The positive shift of the core-electron binding energies for the Cu–In–Se–N film is consistent with that expected from the conduction types of the films. Holes were positioned in the Cu–Se antibonding orbitals of the Cu–In–Se–N film. The analysis using the Auger parameter revealed that the Cu–Se bonding interaction is stronger for the Cu–In–Se–N film than for the Cu–In–Se film.
