Structure and Synthesis of Bi2S3 Nanocrystals for Thermoelectric Device

Characteristics and microstructure of bismuth sulfide (Bi₂S₃) produced by the microwave hydrothermal process are investigated. Bismuth sulfide is a direct band gap material with Eg ~ 1.3 eV and attracts high interest in thermoelectric application. In this work, bismuth sulfide nanostructures can be successfully prepared by a precipitation between bismuth 2-ethylhexanoate and thioacetamide in low-temperature organic solution at about 150 ^oC by the microwave hydrothermal process. The Bi₂S₃ products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and absorption spectra. The composite ratio between Bi and S can be adjusted by varying the ratio between two precursors and was determined by using EDS technique. Thermoelectric properties of the Bi₂S₃will be studied comparatively with those from commercial bulk materials.