Superionic and ion-conducting chalcogenide glasses: Transport regimes and structural features

Chalcogenide glasses are essentially known as amorphous semiconductors with interesting electronic and optical properties. In contrast to vitreous oxide systems which belong mostly to ionic insulators and/or conductors, the ion transport is not common for chalcogenide glasses and was observed for the first time in the seventies. Nevertheless, a higher polarisability of sulphur, selenium or tellurium compared to oxygen and respectively a higher ionic mobility and diffusivity, makes appropriate chalcogenide glassy systems favourable candidates for both fundamental research and practical applications in the field of solid-state ionics. The observed drastically different ion transport regimes that are closely related to the mobile cation distribution in the structure of silver and copper chalcogenide and chalcohalide glasses will be discussed in the present contribution which represents a compilation of recent results obtained by the author.