A review on synthesis, structural properties and applications of metal oxide-based thin film thermoelectric materials

The thin film thermoelectric (TE) materials with higher values of the figure of merit are of special interest due to their promising applications. In this regard, metal oxide thin films are introducing flexible and stretchable devices, a type of next-generation electronic gadgets, and hence possess the potential for TE applications at high temperatures and in novel devices. The mobility, concentration, and scattering of carriers in metal oxide and thin films determine the thermoelectric properties of the materials. The carrier properties can be changed by doping and precise methods of processing, which are not always straightforward. There are, therefore, still many challenges and opportunities to further improve their TE performance and device integration. Future research directions may include exploring new materials and structures, optimizing the doping and fabrication conditions, understanding the transport mechanisms and interfacial effects, and developing scalable and reliable TE devices. In this work, we first introduce the foundation of metal oxide and metal oxide-based TE materials, briefly describe their syntheses, and finally discuss their application underlining the challenges and opportunities.