Controlling Precipitation and Dopant Effects To Achieve Promising Thermoelectric Performance in CaTiO₃

Manipulating microstructures is of considerable importance for controlling the transport of heat and charge. Herein, the microstructure of CaTiO 3 was controlled by adding Nb. Nb serves a dual purpose in the matrix by acting as a dopant, providing extra electrons, and as a phonon scatterer in the lattice. Additionally, it precipitates as a second phase in the Nb-doped CaTiO 3 matrix. Through this approach, we achieved significant enhancements in the power factor, which increased from 2.81 μW cm –1 K –2 in pristine CaTiO 3 to 7.67 μW cm –1 K –2 in CaTi 0.85 Nb 0.15 O 3 at 1031 K. Additionally, we observed a reduction in the lattice thermal conductivity from 2.61 W m –1 K –1 in pristine CaTiO 3 to 2.46 W m –1 K –1 in CaTi 0.85 Nb 0.15 O 3 at the same temperature. As a result, a noteworthy 180% improvement in the overall zT was achieved. Remarkably, the zT value of CaTi 0.9 Nb 0.1 O 3 in our work was found to be 88% higher than the values reported in the existing literature at 1031 K. This work provides a reference for optimizing the thermoelectric properties of CaTiO 3 -based materials by precipitating metal inclusions.