Valence-band photoemission spectra from a variety of alkali halides are shown to be well represented by a phonon-broadened density-of-states histogram with well-determined bandwidths and three or four main peaks. The bandwidths are generally in good agreement with band-structure calculations. The phonon broadening is typically 85% of that calculated for anion core levels, indicating that the valence-band holes are localized.

• Received 12 December 1994

DOI:https://doi.org/10.1103/PhysRevB.51.13675