Chalcogenide glass-ceramics: Functional design and crystallization mechanism

Chalcogenide glasses are defined as a new category of non-crystalline solids on the basis of their characteristic covalent bonds and unique properties, such as broad infrared transmission window, low maximum phonon energy, high optical nonlinearity, semiconductivity, and photosensitivity. Inspired by the great successes that have been achieved in the development of oxide glass-ceramics, functionalized chalcogenide glass-ceramics have received intensive research attention. Moreover, the inherent properties of chalcogenide glasses have been explored and modified through controlled crystallization, to generate novel and unique features. This review aims to present a critical overview of the current state of the art in the controllable fabrication of functionalized chalcogenide glass-ceramics. The first section provides a brief introduction to chalcogenide glasses and glass ceramics. The succeeding sections detail the fabrication strategies of chalcogenide glass ceramics with various functions through different precipitated crystals and microstructures. This review provides a discussion of the mechanism that underlie the resultant properties of chalcogenide glass-ceramics. Furthermore, the crystallization mechanisms of chalcogenide glasses are discussed through the comparison of molecular-scale and nanoscale phase separation assisted crystallization mechanisms in oxide and oxyfluoride glasses. Finally, the remain section presents the key questions that remain unanswered, as well as provide perspectives on the future research trends. (C) 2017 Elsevier Ltd. All rights reserved.