Preparation and enhanced thermoelectric performance of Pb-doped tetrahedrite Cu12-xPbxSb4S13

Pb-doped tetrahedrite Cu12-xPbxSb4S13 (x = 0, 0.25, 0.50, 0.75, 1.00, 1.25 and 1.50) samples were prepared and their thermoelectric properties were investigated in the temperature range from 300 K to 723 K. The results show that Pb is successfully doped in Cu(1) site, which brings about both 10-118% increase in Seebeck coefficient owing to the decrease of hole concentration and 87-168% decrease in thermal conductivity due to the enhanced phonon scattering by the dopant atoms. As a result, a maximum ZT = 0.8 at 723 K is achieved for Cu11PbSb4S13, which is ∼43% larger than that of pristine Cu12Sb4S13. Present results demonstrate that Pb is an effective dopant to elevate thermoelectric performance of Cu12Sb4S13.