Abstract
Chalcogenides (Se, Te and S) are one of the interesting classes of materials studied so far. They have potential applications in phase change recording, memory and switching and various other solid state electronic devices. These materials got a great deal of attention of the scientists worldwide due to their low phonon energy, infrared transparency, large value of refractive index, high photosensitivity, reversible phase transformation etc. There are several techniques for the synthesis of chalcogenide materials, which include melt quenching, thermal evaporation, sputtering, chemical vapor deposition etc. Among all these techniques, melt quenching is one of the simplest and popular techniques for producing chalcogenide glasses. Recently, a lot of work is focussed on production of chalcogenides at nanoscale. The understanding of electrical, optical and thermal properties of these chalcogenides at nanoscale is of great interest both from fundamental and technological point of view. Due to their interesting physical properties, these nanochalcogenides has raised considerable deal of research interest followed by technological applications in the field of micro/optoelectronics. The structure of chalcogenides is disordered at the atomic scale. Therefore, the nanostructures of these materials can easily be tailored and may yield a greater variety than that of crystalline nanostructures. The synthesis of chalcogenide nanostructures in the form of nanoparticles, nanobelts, nanorods, and nanowires has stimulated intense research activity due to their improved properties at nanoscale. With these interesting results, the nano-chalcogenides have become the focus of attention and are expected to present interesting properties. A dramatic change in the physical and chemical properties of these materials is observed due to size reduction. Moreover, the work on the synthesis and characterization of nano-chalcogenides is still in the primarily stages and accordingly, overall features have not been explored so far. Therefore, more research work on these nanochalcogenides is needed for complete understanding of the mechanism responsible for change in properties in these materials at nanoscale. This chapter provides a comprehensive review of chalcogenides and nanochalcogenides, their synthesis and applications.