Recent progress of halide perovskites for thermoelectric application

The application of halide perovskites (HPs) working in the optoelectronic field has attracted intense attention and experienced rapid development. The ultralow thermal conductivity of HPs makes them also promising candidates for thermoelectric application. Recently, combined with the optimization of other relevant thermoelectric parameters, the performance of HPs based thermoelectrics has been significantly promoted. Here, we review the experimental progress on modulating the thermoelectric performance of HPs from the perspective of electrical conductivity optimization. First, we give an overview of the reports and understanding of ultralow thermal conductivity of different types of HPs. Then we review the research progress on improving thermoelectric properties of HPs with emphasis on optimizing their electrical conductivity, including reduction of charge transport obstructions and various doping methods. Finally, we also point out several problems in halide perovskite-based thermoelectric devices, hoping to give guidelines for further investigations.