OPTICAL-PROPERTIES OF AMORPHOUS AS2SE3 AS2S8 MULTILAYERS/

Photoluminescence, excitation spectra and optical absorption spectra o f amorphous chalcogenide multilayers of As2Se3/As2S8 were studied. Lum inescence spectra of the multilayers were similar to those of the a-As 2Se3 single layer, However, excitation spectra of multilayers were dif ferent from a-As2Se3, namely a blue shift of the spectra was observed for multilayers. Blue shift of the optical absorption spectra was obse rved with a decrease of the well-layer thickness. Experimental results are discussed using a configurational-coordinate diagram, where lumin escence centers are localized and the extended states occupied by exci ted carriers are quantized.