Optimized thermoelectric performance driven by A‐site deficient in Sr_xLa_0.1TiO_3−δ/TiO_2−y composites

Abstract

For thermoelectric applications at high temperatures, perovskite SrTiO3 is a promising contender as an n‐type oxide thermoelectric (TE) material. In this work, SrxLa0.1TiO3−δ/TiO2−y composite ceramics were successfully synthesized by solid state reaction, using a combination of A‐site cation vacancy and composite fabrication. Through X‐ray diffractometer and scanning electron microscopy analysis, a complex microstructure composed of two kinds of titanium oxides was formed after reductive sintering and annealing. In addition, controlling the content of Sr vacancies in the SrxLa0.1TiO3−δ matrix increased the thermoelectric power factor (PF) by optimizing the weighted mobility in the composite, resulting in the highest PF of 425.8 μW m−1 K−2 and the maximum ZT of 0.16 for the Sr0.875La0.1TiO3−δ/TiO2−y composite through the synergistic optimization of electrical and thermal transport properties. The strategy proposed in this study of design A‐site‐deficient composites with nano‐sized metal paved a new way to fabricate high performance oxide thermoelectric materials.