Optical properties of amorphous As2Se3/As2S8 multilayers

Photoluminescence, excitation spectra and optical absorption spectra of amorphous chalcogenide multilayers of As2Se3/As2S8 were studied. Luminescence spectra of the multilayers were similar to those of the a-As2Se3 single layer, However, excitation spectra of multilayers were different from a-As2Se3, namely a blue shift of the spectra was observed for multilayers. Blue shift of the optical absorption spectra was observed with a decrease of the well-layer thickness. Experimental results are discussed using a configurational-coordinate diagram, where luminescence centers are localized and the extended states occupied by excited carriers are quantized.