Thermoelectric properties of hydrothermally synthesized Bi2Te3−xSex nanocrystals

A chemical route combined with a subsequent spark plasma sintering technique was successfully utilized to synthesize n-type Se-substituted ternary Bi2Te3−xSex (0 ⩽ x ⩽ 0.6). We investigated the effect of Se doping on the thermoelectric properties of the Bi2Te3 nanostructured bulk materials. The results indicate that Se doping is an efficient way to reduce the thermal conductivity as compared to that of Bi2Te3 presumably due to enhanced (dopant) scattering of phonons. The maximum thermoelectric figure-of-merit, ZT, is 0.7 at 485 K for Bi2Te2.55Se0.45.