Sub-gap excitation effects in As2S3 glass

Abstract The mechanism of photoexpansion (PE) has been studied in conjunction with photoconduction (PC) and photoluminescence (PL) characteristics for As2S3 glass. In spectrum-intensity dependence measured at room temperature the PE resembles the PC, while the PE shows a similar temperature dependence to that of the PL. These features are discussed in relation to the band-tail structure in chalcogenide glasses and we suggest that electron–hole pairs are responsible for the PE.