Improved power factor of Ag-doped calcium cobalt oxide (Ca2Co2O5) prepared by hot pressing

The Ag-doped calcium cobalt oxide (Ca2Co2-xAgxO5, x = 0, 0.03, 0.06, and 0.09) was synthesized by the polymerized complex method following hot press sintering. Temperature dependence of the Seebeck coefficient and electrical resistivity were investigated using standard dc four-probe technique in a ZEM-3 measurement system in temperature range 300–862 K. Maximum value of the Seebeck coefficient was 178 μV K-1 with Ag contents of 0 and 0.03 at 862 K. Highest power factor of 173 μW m-1 K-2 and lowest electrical resistivity of 174 μΩ m were obtained at Ag content of 0.09 and at 862 K, respectively. Significant improvement of the power factor of Ca2Co2-xAgxO5 was mainly due to decrease in electrical resistivity. •Ag-doped Ca2Co2O5 were prepared by the polymerized complex method and hot pressing.•Highest power factor of 173 μW m-1K-2 and lowest electrical resistivity of 174 μO m were obtained.•The power factor increased as a result of improvement of carrier concentration.