Metal Halide Perovskites as Emerging Thermoelectric Materials

In addition to the broadly anticipated use of metal halide perovskites in photovoltaics and light-emitting devices, they also hold a great promise as cost-effective thermoelectrics, as they may offer an ultra-low thermal conductivity combined with a high Seebeck coefficient. This Review summarizes the recent advances in theoretical analysis and experimental studies of the thermoelectric properties of these materials, with a particular focus on organic-inorganic (hybrid) halide perovskites and low-dimensional analogues. After a short introduction of figures of merits of thermoelectric materials, we consider measurement methods used to characterize thermoelectric materials and outline some difficulties in applying those methods to perovskites, since accurate measurements are essential for further progress of this emerging research area. We then outline in detail the current progress achieved in metal halide perovskite thermoelectrics and offer a detailed discussion of possible strategies to resolve the discrepancy between their high theoretically predicted ZT values (1-2 at room temperature) and still rather low (below 0.2) experimental values.