Spectrophotometric analyses on electronic structures of glide dislocation cores in ZnS

Abstract It has been reported that dislocations in ZnS can trap photoexcited carriers and then undergo core reconstruction. However, electronic states of the trapped carriers at the reconstructed dislocations were not detected experimentally. In this study, unique ultraviolet (UV)–visible–infrared (IR) transmission measurements by using a spectrophotometer with UV pump beam were performed for deformed ZnS single crystals having glide dislocations. Optical transmission values of the deformed specimens decreased by the pump beam illumination apparently. Additionally, the optical transmission reductions increased more with rising plastic strains, namely, rising dislocation density. Since the UV pump beam can produce photoexcited carriers of electrons and holes, it is expected that the glide dislocations introduced in the deformed specimens undergo core reconstruction due to carrier trapping. Therefore, it is thought that the observed reduction in optical transmission of the deformed specimens is ascribed to photoabsorption due to in‐gap states localized at the reconstructed partial dislocation cores. Moreover, time‐dependent transmission measurements revealed that the core reconstruction proceed rapidly while the opposite processes are quite slow, which may be closely related to atomic structure changes of the glide dislocation cores due to the additional pump beam illumination.