Thermoelectric Generator Using Polyaniline-Coated Sb₂Se₃/β-Cu₂Se Flexible Thermoelectric Films

Herein, Sb₂Se₃ and β-Cu₂Se nanowires are synthesized via hydrothermal reaction and water evaporation-induced self-assembly methods, respectively. The successful syntheses and morphologies of the Sb₂Se₃ and β-Cu₂Se nanowires are confirmed via X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, field emission scanning electron microscopy (FE-SEM), and field emission transmission electron microscopy (FE-TEM). Sb₂Se₃ materials have low electrical conductivity which limits application to the thermoelectric generator. To improve the electrical conductivity of the Sb₂Se₃ and β-Cu₂Se nanowires, polyaniline (PANI) is coated onto the surface and confirmed via Fourier-transform infrared spectroscopy (FT-IR), FE-TEM, and XPS analysis. After coating PANI, the electrical conductivities of Sb₂Se₃/β-Cu₂Se/PANI composites were increased. The thermoelectric performance of the flexible Sb₂Se₃/β-Cu₂Se/PANI films is then measured, and the 70%-Sb₂Se₃/30%-β-Cu₂Se/PANI film is shown to provide the highest power factor of 181.61 μW/m·K² at 473 K. In addition, a thermoelectric generator consisting of five legs of the 70%-Sb₂Se₃/30%-β-Cu₂Se/PANI film is constructed and shown to provide an open-circuit voltage of 7.9 mV and an output power of 80.1 nW at ΔT = 30 K. This study demonstrates that the combination of inorganic thermoelectric materials and flexible polymers can generate power in wearable or portable devices.