Study of light-induced vector changes in the local atomic structure of As–Se glasses by EXAFS

Abstract We have observed light-induced vector changes in the local structure of As–Se glasses using extended X-ray absorption fine structure (EXAFS) experiments with in situ laser illumination. Local structure around As and Se atoms was determined for as-prepared as well as annealed a-As 40 Se 60 films, which were exposed to bandgap light of polarization parallel and perpendicular to that of the X-rays. For the as-prepared film, the nearest neighbor bond distance around Se atoms increases, the magnitude of which varies with the polarization of light, thus confirming our previous observations on a-As 50 Se 50 films. These results give an atomistic indication of a light-induced vector expansion in any material, and provide insight of the mechanisms of the light-induced atom displacements.