Bi2S3 as a Promising ThermoelectricMaterial:Back and Forth

Thermoelectric conversion technology based on thermoelectric materials can directly convert heatandelectricity and is extensively used in waste heat recovery, semiconductor refrigeration, and spaceexploration.Currently, bismuth telluride (Bi2Te3) thermoelectric materials are the best in terms of room-temperatureperformance and have been commercialized. Compared with commercial Bi2Te3 thermoelectricmaterialsofthe same family (III-VI group), bismuth sulfide (Bi2S3) thermoelectric materials have the uniqueadvantagesof being abundant, low-cost, and environmentally friendly. However, the thermoelectric propertiesofBi2S3are limited by its low electrical conductivity. In recent years, with the development of preparationmethodsand characterization tools, many studies have emerged to improve the thermoelectric propertiesofBi2S3materials. Herein, the preparation of Bi2S3 thermoelectric materials and the implications of theprocessontheir thermoelectric properties are summarized. The advances made in composition, structureandotherstrategies to optimize the thermoelectric properties of Bi2S3 are highlighted, and the current challengesforthe development of Bi2S3 thermoelectric materials and potential future research directions are alsodiscussed.Keywords: Bi2S3, thermoelectric, nanorods, electrical conductivity