Synergistically enhanced thermoelectric performance by optimizing the composite ratio between hydrothermal Sb2Se3 and self-assembled β-Cu2Se nanowires

Abstract

Hydrothermal reactions and water-evaporation-induced self-assembly were employed to synthesize Sb₂Se₃ and β-Cu₂Se nanowires, respectively, with diameters of 100–200 nm and lengths of 2–3 μm. The resulting nanowires were subsequently characterized using XRD, XPS, FE-SEM, FE-TEM, and EDS elemental mapping to determine their physical, morphological, and chemical properties. Sb₂Se₃ nanowires exhibited low electrical conductivities and high Seebeck coefficients, whereas β-Cu₂Se nanowires had high electrical conductivities and low Seebeck coefficients. Increasing the β-Cu₂Se content in the mixtures containing Sb₂Se₃ and β-Cu₂Se nanowires concomitantly enhanced the electrical conductivities but lowered the Seebeck coefficients. The nanowire sample with 30% β-Cu₂Se and 70% Sb₂Se₃ exhibited maximal power factor and figure merit values of 389.19 μW m⁻¹ K² and 0.288, respectively, at 473 K.