Densities of states of black phosphorus by soft X-ray spectroscopy

Abstract
We report the results of a soft X-ray investigation of the valence and conduction states of black phosphorus from which the p and s states distributions are obtained separately. The presence of pure p states is found at the upper part of the valence band. Good agreement is found with recent X-ray photoelectron spectroscopy data and with a theoretical density-of-states calculation performed for the same allotrope. The p-like densities of states of the valence band for black and red amorphous phosphorus are compared.