Investigation of SNSE GEX se te and ZNSB based semiconductor nanostructures for thermoelectric applications

Abstract

Thermoelectrics is a promising technology to convert thermal energy into electrical energy and it is pivotal to identify the impressive materials for realizing higher thermoelectric efficiency. The performance of a thermoelectric material can be determined by the figure of merit, ZT= (S2and#963; T)/and#61547;, where S-Seebeck coefficient, and#963;-electrical conductivity, T-absolute temperature and and#61547;-total thermal conductivity. All these parameters are interrelated with each other and thereby it is very challenging to enhance the performance of a thermoelectric material. The ZT of a material can be persuaded by the electron transport properties and thermal transport properties. Bismuth telluride, antimony telluride are the promising materials for low temperature applications. Silicon-Germanium is a well-known thermoelectric materials for high temperature applications. newlineGroup IV-VI compounds such as PbX (X=Se,Te,S) SnX (X=Se, Te, S), Cu2X (X=Se, Te, S), Zn4Sb3, Mg2X (X = Si, Sn, Ge), In4Se3, and skutterudites have shown good thermoelectric performances in intermediate range of temperatures (600-900K). Among these compounds, lead chalcogenide-based thermoelectric materials grabbed much attention from 2011, which is evidenced by a high ZT value. However, their toxicity restricted their large-scale production. In recent years, GeX (x= Se, Te), SnSe and ZnSb materials have been a great choice for lead-free materials with attractive thermoelectric properties in the intermediate temperature range (600-900 K). Several fabrication methods were employed to prepare the tin- and germanium-based chalcogenide and ZnSb materials such as melt quenching and solvothermal methods. The materials were annealed at 505and#61616;C in vacuum for 12 hrs, followed by consolidation under hot pressing or spark plasma sintering technique. newline