Strategies for manipulating thermoelectric properties of layered oxides

Thermoelectric materials could transform thermal energy to electrical energy, and they have come into view as a possible new energy to replace fossil energy. Layered oxide thermoelectric materials, as two-dimensional materials and oxides, have obtained special attention for their artificial superlattice properties, anisotropic transport, thermal stability, and environmental friendliness. Cobalt oxides and oxyselenides, two typical layered oxide thermoelectric materials, show excellent performance (ZTmax ≥ 1.5). In this review, we compared the thermoelectric performance of layered oxides with that of PbTe. Also, effective performance optimization strategies and their physical mechanisms for layered oxides are clarified, such as lead-in vacancy, single crystal preparation, texture, modulation doping, band structure modification, interdisciplinary spin entropy, and valence bond engineering. Finally, the future development trend of layered oxides and innovative performance optimization strategies are discussed. This review shows that layered oxides are promising thermoelectric materials, and new strategies with innovative theories for performance optimization are the key to their future development.