Publication

Abstract : Thermoelectric (TE) materials have been considered as a vital candidate for waste heat recovery. However, the high cost of using highly purified metallic elements often limits their large-scale application. In this context, tetrahedrite-based materials have been explored as a cost-effective and sustainable alternative, distinguished by their natural abundance in copper ore residues and their widespread occurrence among sulfosalts. The current study details the role of nanocomposite doping in tailoring the TE properties of p-type tetrahedrite. Three samples have been synthesized employing a hot press at 773 K namely undoped Cu10Mn2Sb4S13 designated as XA+0% Nb2O5 and its niobium pentoxide (Nb2O5)-doped counterparts 0.5 and 1.0 vol.% Nb2O5 designated as XA+0.5% Nb2O5 and XA+1.0% Nb2O5 respectively-a nomenclature adopted consistently throughout this manuscript. Moreover, Mn substitution at the Cu site proved effective in tuning the carrier concentration while simultaneously enhancing phonon scattering, thereby improving the overall power factor. The incorporation of Nb2O5 further improved electronic transport by an energy-filtering mechanism. Among all the synthesized samples, XA+0.5% Nb2O5 exhibited superior performance, with a Seebeck coefficient of ∿363 μV/K at 573 K in comparison to XA+1.0% Nb2O5 (∿ 220 μV/K) and XA+0% Nb2O5 (∿ 242 μV/K). In addition, XA+0.5% Nb2O5 demonstrated an electrical conductivity of ∿ 1.18 × 103 S/m and a power factor of ∿ 156.38 μW/mK2 at 573 K, which is ∿ four times higher than XA+1.0% Nb2O5 and ∿ 12% greater than XA+0% Nb2O5. Thus, these findings clearly highlight nanocomposite engineering as an effective approach for optimizing the TE performance.