Optimization of thermoelectric properties of CoSb3 materials by increasing the complexity of chemical structure

As a representative thermoelectric material in the middle temperature region, skutterudite CoSb3 exhibits stable structure and excellent thermoelectric properties. Because of the special cage structure of CoSb3, it has been recognized that the thermoelectric performance of CoSb3 can be optimized by filling or doping. In this paper, we have studied the effects of doping alone, doping and filling phase combination, and the increase of atomic filling ratio on the thermoelectric properties of CoSb3 materials. In addition, under high temperature and high pressure (HPHT), the synthesizing cycle of CoSb3 material is only half an hour. The results show that the thermal conductivity of the samples decreases with the increase of the type and proportion of filled atoms. Finally, the maximum thermoelectric figure of merit ZT value of In0.2Ba0.2Co4Sb11.3Te0.7 reached 0.91 at 773K.