Photoemission and inverse-photoemission studies of glassy AsxSe1−x

Valence-band and conduction-band electronic structure of glassy (g-) AsxSe1−x with x=0, 0.16, 0.34, 0.40, 0.44 and 0.55 has been investigated by means of in situ measurements of photoemission and inverse-photoemission spectra. The spectra exhibit changes at x=0.4 in the energy position of Se 4p lone-pair states, the band gap energy and the widths of valence bands and the main peak in the inverse-photoemission spectra. Two peak structures derived from Se-chains also disappear at x=0.4. These changes support the percolation phenomenon predicted for g-AsxSe1−x.