Simultaneous optimization of power factor and thermal conductivity via Te and Se double substitution in Cu12Sb4S13 tetrahedrite

• DOI: 10.1016/j.scriptamat.2020.07.036
• Publication Date: 2020-07-24T03:23:07Z
• Authors: Umasankar Rout; Sahil Tippireddy; Katharina Werbach; Padaikathan Pamba...; Gerda Rogl; Peter Rogl; Ramesh Chandra Ma...
• Keywords: EFFICIENCY; Tetrahedrite; 103018 Materialphysik; TENNANTITE; Mechanical properties; PERFORMANCE; 01 natural sciences; 7. Clean energy; 104017 Physikalische Chemie; 0104 chemical sciences; Raman spectroscopy; 104017 Physical chemistry; Electrical properties; Density functional theory (DFT); PBTE; THERMOELECTRIC PROPERTIES; 103018 Materials physics; SB

The present study reports the structural, electronic, elastic, and thermoelectric properties of Cu12Sb3.9Te0.1S13-xSex (x = 0, 0.1, 0.5, 0.75 and 1) tetrahedrite. The thermal conductivity was reduced due to charge carrier compensation (by Te), weakening of the Sb-S bond and local chemical disorder (induced by Se), resulting in a low mean sound velocity. Simultaneously, the power-factor was maintained high from an enhancement of the density of states near the Fermi level due to Se. Consequently, a maximum figure of merit similar to 0.84 at 673 K was achieved for the Cu12Sb3.9Te0.1S12.5Se0.5 sample due to concomitant optimisation of the power-factor and thermal conductivity.