Ternary selenide CuAgSe shows a great potential as a new promising thermoelectric material due to the superior carrier mobility and low lattice thermal conductivity. In this study, we doped Te at Se-sites and systematically studied the effect of Te-doping on the thermoelectric properties of low-temperature CuAgSe phase (β-CuAgSe). It is found that the Te doping limit in β-CuAgSe is around 0.15. The longitudinal resistivity and Hall resistivity measurements under magnetic field suggest that Te-doping exerts little effect on the band structure and the low-mobility carriers (holes) contribute weakly to the electrical transports in all Te-doped samples. Thus, the p-n transition and accompanying abrupt Seebeck coefficient decrease at elevated temperature, which are quite common in the non-stoichiometric β-CuAgSe samples, were not observed in Te-doped samples. Although the electrical conductivity of Te-doped samples is reduced due to the decreased carrier concentration and mobility, the significantly decreased thermal conductivity ensures the Te-doped samples still maintaining similar or slightly higher thermoelectric figure of merit (zT) as compared with that of the stoichiometric β-CuAgSe. The maximum zT around 0.7 at 450 K is obtained in CuAgSe0.95Te0.05.

Correction for ‘Thermoelectric properties of Te-doped ternary CuAgSe compounds’ by P. F. Qiu et al., J. Mater. Chem. A, 2015, DOI: 10.1039/c5ta06780d.