Review of current high-ZT thermoelectric materials

Thermoelectric materials are capable of converting heat and electricity to each other. Thermoelectric devices can be miniaturized and highly integrated with existing semiconductor chip systems with microgenerators or microrefrigerators. After years of research and accumulation, BiTe series, SnSe series, CuSe series, half-Heusler series, multicomponent oxides series, organic–inorganic composites series, and GeTe/PbTe series have been found to have excellent thermoelectric properties. According to theoretical calculation, when the diameter of Bi2Te3 nanowires is 5 Å, the ZT value reaches 14, and graphdiyne has a ZT value of 4.8 at 300 K. Experimental measurements revealed that the ZT value of n-type SnSe reached 2.8. This review would focus on the updated experimental and theoretical achievements of seven kinds of materials, including BiTe series, SnSe series, CuSe series, multicomponent oxides, half-Heusler alloys, organic–inorganic composites, and GeTe/PbTe series. The preparation method, microstructure characteristics, device structure, and thermoelectric properties of each material will be described in detail. By analyzing the performance of these materials, three possible development directions are put forward for how to further improve the thermoelectric properties of materials.