All-Inorganic Halide Perovskites Boost High-Ranged Figure-of-Merit in Bi<sub>0.4</sub>Sb<sub>1.6</sub>Te<sub>3</sub> for Thermoelectric Cooling and Low-Grade Heat Recovery.

Jin, Kangpeng; Yang, Zhiya; Fu, Liangwei; Lou, Yue; Xu, Pengfei; Huang, Ming; Shi, Zhan; Xu, Biao · ACS Nano · 2024

basic_science · Level V

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Abstract

The all-inorganic halide perovskite CsPbX<sub>3</sub> (X = Cl, Br, or I) offers various advantages, such as tunable electronic structure and high carrier mobility. However, its potential application in thermoelectric materials remains underexplored. In this study, we propose a simple yet effective method to synthesize a CsPbX<sub>3</sub>/Bi<sub>0.4</sub>Sb<sub>1.6</sub>Te<sub>3</sub> (BST) nanocomposite by sintering a uniformly mixed raw powder. The intrinsic excitation of the BST system is suppressed by exploiting the rich phase structure and tunable electrical transport properties of CsPbX<sub>3</sub>, and the thermoelectric properties were synergistically optimized. Notably, for CsPbI<sub>3</sub>, its phase-transition-induced dislocation arrays together with low group velocities drastically reduce thermal conductivity. As a result, the composite achieves an ultrahigh average figure-of-merit (<i>ZT</i>) of 1.4 from 298 to 523 K. The two-pair TE module demonstrates a superior conversion efficiency of 7.3%. This study expands the potential applications of inorganic halide perovskites, into thermoelectrics.