One-dimensional electronic states inGa2Se3on Si(001):As

Abstract

Gallium selenide Ga2Se3 is a III-VI chalcogenide material whose intrinsic cation vacancy ordering into one dimensional chains has been predicted to result in a one dimensional band at the valence-band maximum VBM. The electronic structure of Ga2Se3 thin films on Si001:As is studied with angle-resolved photoemission spectroscopy. The integrated density of states and the dispersion exhibit good agreement with that predicted by published density-functional theory results. Consistent with a one dimensional state, the electronic states at the VBM show no dispersion perpendicular to the vacancy chains. The Se-Ga bond length from extended x-ray absorption fine structure is 2.34 A. Low-energy electron-diffraction results indicate that the surface is characterized by nanometer-scale 111 facets, consistent with previous scanning tunneling microscopy results.