Work

NbC stabilized doping in SrTiO3 for thermoelectric energy harvesting above 1000 °C

Year: 2026

Type: article

Abstract: High-temperature thermoelectric materials with robust thermal stability against phase transition and elemental volatilization are essential for space exploration applications above 1000 °C. Niobium-doped strontium titanate is a promising n-type high-temperature thermoelectric material due to its high melting point and tunable electrical transport properties. However, conventional carbothermal reduction strategies used to eliminate grain boundary barriers readily induce de-doping effect, thereby deteriorating the high-temperature thermoelectric stability of the material. Herein, we propose Niobium carbide (NbC) as a mild reductant that can effectively reduce double Schottky barrier while maintaining the Nb doping equilibrium of the multi-doped Sr 0.9 La 0.05 Sm 0.05 Ti 0.95 Nb 0.05 O 3 (SLSTN) ceramics even at high temperature. NbC enhances the electrical performance of SLSTN while maintaining a high Seebeck coefficient, achieving a stable high power factor. The composite with 0.5%(mass fraction) NbC delivers a peak zT value of 0.41 at 1073 K. Moreover, by constructing a Ni coating /(SLSTN/Ni) transition layer to reduce the interfacial contact resistance, the thermoelectric devices composed of four n-type legs achieve an open-circuit voltage of 0.38 V and a maximum output power of 284 mW at a hot-end temperature of 1045.4 °C. Therefore, this work provides an efficient strategy for optimizing oxide based thermoelectric ceramics and devices towards high temperature application.

Source: Journal of Materiomics

DOI: 10.1016/j.jmat.2026.101315