EFFECT OF ANNEALING TEMPERATURE ON THE STRUCTURAL AND THERMOELECTRIC PROPERTIES OF CuFeS2 NANOPARTICLES PREPARED BY THE HYDROTHERMAL METHOD

The current study described precise and simple hydrothermal method used to synthesize CuFeS2 nanoparticles. The thermoelectric properties of CuFeS2 nanoparticles were studied under different conditions of annealing treatment. The phase structure, functional groups, and thermal stability of the CuFeS2 nanoparticles samples were analyzed via X-ray diffractometer (XRD), Fourier transform infrared spectroscopy (FT-IR), and thermogravimetric analysis (TGA). The X-ray diffraction (XRD) results of the synthesized nanoparticles closely matched the CuFeS2 chalcopyrite patterns. FT-IR measurements confirmed the presence of the characteristic S-O, Fe-S, and O-H groups in the structure of the prepared nanoparticles. The TGA results indicate that the CuFeS2 nanoparticles are thermally stable below 650°C. The scan electron microscope (SEM) measurements revealed that the particle size of all the samples was less than 100 nm after the annealing treatment. The optical measurements showed that the absorbance edges of the CuFeS2 samples shifted to longer wavelengths after the annealing treatment. The thermoelectric measurements indicated that the annealing treatment modulated the electrical conductivity, Seebeck coefficient, power factor, and thermal conductivity of the CuFeS2 samples.