The effect of various dopants on thermoelectric properties of Bi/sub 2/(Te/sub 0.9/Se/sub 0.1/)/sub 3/ polycrystals

In this study, mechanical alloying followed by pulse discharge sintering (MA-PDS) was employed to synthesize the bulk Bi/sub 2/(Te/sub 0.9/Se/sub 0.1/)/sub 3/ thermoelectric materials and then the compacts were spread by hot-pressing process. The additives we selected several metal iodide and bromide (AgBr, CuBr, CuBr/sub 2/, AgI). All dopants increase the carrier concentration and power-factor. The excellent metal element of dopants were silver and copper. Moreover, the effect of spreading on the crystal orientation and thermoelectric performance of the compacts was investigated. The microstructural characterizations of the spread compacts by XRD and SEM indicated a high crystallographic orientation after spreading. Furthermore, power-factor and carrier mobility was increased by the high crystal orientation.