Change in optical anisotropy of localized states associated with reversible photostructural change in a-As2S3 films

Abstract In annealed As 2 S 3 films, band-gap illumination induces red-shift of optical absorption edge and increase of polarization memory of photoluminescence. In the case of illumination with linearly polarized light, anisotropy is induced in both. From dependence of the edge shift, the anisotropy of the absorption edge and the increase of polarization memory on the illumination conditions (temperature, photon energy and intensity), it was found that there was a strong correlation between the latter two but the edge shift had no correlation with the latters. The latter two reflect the increase of the optical anisotropy of the localized states and the reorientation of the anisotropy axes to the direction perpendicular to the polarization vector of the illumination light, but the bulk change in the structure gives the edge shift.