Optimization of the Seebeck coefficient and electrical conductivity in Sb₂Se₃/rGO nanocomposites by controlling the rGO contents

Abstract This manuscript reported a high power factor in Sb₂Se₃/rGO nanocomposites by optimizing the Seebeck coefficient and electrical conductivity. Pristine rGO and Sb 2 Se 3 nanoparticles were synthesized by hydrothermal technique and subsequently composite was prepared by solid state reaction method using different contents (weight) of rGO ranging from10-40%. XRD data confirmed the graphitic carbon and orthorhombic structures of as grown rGO and Sb 2 Se 3 nanoparticles respectively. The Sb₂Se₃/rGO nanocomposites sustained the orthorhombic structure but it found to be degraded with increasing the concentration of rGO. This degradation was further verified by performing the Raman and UV-Vis spectroscopic measurements. Seebeck data suggested that even the highest electrical conductivity of 35 S/cm for rGO and the highest value of Seebeck coefficient of 998 µV/K for Sb 2 Se 3 nanoparticles resulted very poor power factors for both rGO and Sb 2 Se 3 nanoparticles (0.6 and 0.8 µW/m.K 2 respectively). To optimize the electrical conductivity and the Seebeck coefficient, the concentration of rGO in Sb 2 Se 3 /rGO composite was varied and it was found that 10% rGO is suitable to achieve highest power factor of 2.4 µW/m.K 2 . This reported power factor is supposed to be the highest value for Sb 2 Se 3 /rGO composite having 10% rGO reported in the literature according to the best of our knowledge.