Nanoarchitectonics of TlBiS ₂ poly crystals grown by melt temperature oscillation method

Abstract Thallium Bismuth Sulphide (TlBiS 2 ) polycrystalline material was synthesized by melt temperature oscillation method using high-purity elemental constituents. Structural characterization using powder x-ray diffraction (XRD) confirmed the formation of the Trigonal structure with well-defined unit cell parameters. Raman spectroscopy revealed distinct vibrational modes characteristic of the compound, while field emission scanning electron microscopy (FESEM) demonstrated a fused nano-plate-like morphology. X-ray photoelectron spectroscopy (XPS) provided evidence of the expected chemical states through characteristic binding energy shifts. Electrical transport measurements indicated notable values for Hall carrier concentration and mobility. Room temperature Seebeck coefficient of 120 μV K −1 was observed, highlighting the materials potential for thermoelectric applications. Furthermore, the electronic thermal conductivity, calculated using the Wiedemann–Franz law, was found to be 0.003381 W·m −1 ·K −1 , significantly lower than that of conventional Bi 2 Te 3 -based thermoelectric materials. These results underscore the promising thermoelectric performance of TlBiS 2 and its potential utility in energy conversion technologies.