Thermoelectric properties of Ti-doped WO3 ceramics

The influences of titanium dioxide (TiO2) on thermoelectric properties of tungsten trioxide (WO3) ceramics were investigated. In the sintered samples, the grain size of the ceramics was evidently reduced while the dense of the ceramics was improved due to the addition of TiO2. Doping WO3 with TiO2 obviously raised the electrical conductivity (sigma) of the ceramics by about two orders of magnitude. The absolute value of Seebeck coefficient (vertical bar S vertical bar) of the doped samples was enhanced because of the small grain size. Thus, the magnitude of the power factor (sigma S-2) was uplifted strongly by adding TiO2. In addition, there existed an optimum doping concentration of TiO2 in WO3 to obtain a better power factor.