ICT2014 Abstracts

BiAgSeS shows n-type conduction behavior with intrinsically low thermal conductivity. Like most high performance thermoelectric materials, it also involved a complicated synthesis procedure that is expensive and nonscalable for large quantity production. In this study, we have successfully obtained BiAgSeS single phase via combustion synthesis technology within only 1 minute. Combined with plasma activated sintering method, highly dense pellets with over 99.8% relative density were obtained. The thermoelectric transport properties were measured from room temperature to 823 K. The dimensionless thermoelectric figure of merit ZT increases with temperature and reaches a maximum value of 0.46 at 823K for the pristine BiAgSeS sample. Also we first found and confirmed that BiAgSeS undergoes a phase transition in the range of 220~230℃，and the thermal conductivity shows a sudden drop when phase transition happens, which is beneficial to optimize thermoelectric performance and definitely enriches solid-state chemistry and materials science. The thermoelectric properties of BiAgSeS can be further improved by doping to an optimum carrier concentration.