Enhanced thermoelectric performance of V2O5 bulk-type pellet nanodevices by tungsten doping

Abstract

Bulk-type pellet thermoelectric devices were fabricated by pressing tungsten (W)-doped V2O5 (WxV2-xO5) nanospheres that were synthesized by chemical reaction, and their performance was studied. The sizes of the synthesized WxV2-xO5 nanospheres (x = 0, 0.04, 0.08, and 0.12) were measured as 259 +/- 25, 184 +/- 16, 178 +/- 16, and 180 +/- 21 nm, respectively. The thermoelectric properties were analyzed by obtaining the thermoelectric figure of merit (ZT) using the measured thermal conductivity, electrical conductivity, and Seebeck coefficient in the temperature range of 300-773 K. The thermal conductivity was decreased by the W doping, while the electrical conductivity was increased. As a result, the ZT value increased with the doping concentration, and the maximum ZT value of the W0.08V1.92O5 pellet reached 4.73 x 10(-3), which is 3.3 times larger than that of a pure V2O5 pellet at 773 K.