The effect of various dopants on thermoelectric properties of Bi2(Te0.9Se0.1)3polycrystals


A. Nozue1, Y.H Park2,A. Kawasaki3


1RefrigerationResearch Laboratory Engineering Division, Matsushita Home Appliances Company,Matsushita Electric Industrial Co., Ltd., Kusatsu 525-8555, Japan

2Pusan National University,Pusan 609-735, Korea

3Tohoku University, Sendai980-8579, Japan


In this study,mechanical alloying followed by pulse discharge sintering (MA-PDS) was employedto synthesize bulk Bi2(Te0.9Se0.1)3thermoelectric materials. The compacts were then spread by hot-pressingprocess. We selected several metal iodide and bromide materials as additives.All dopants increase the carrier concentration and power-factor. The bestmetallic elements for the dopants were silver and copper. Moreover, the effectof spreading on the crystal orientation and thermoelectric performance of thecompacts was investigated. The microstructural characterizations of the spreadcompacts by XRD and SEM indicated a high crystallographic orientation afterspreading. Furthermore, power-factor and carrier mobility were increased by thehigh crystal orientation.