Low lattice thermal conductivity and improved power factor in Ga-substituted CuSbTe2 alloys for mid-temperature thermoelectric application

I-V-VI based thermoelectric materials recently attracted the great attention due to their unique functional properties. Herein we have performed the systematic study of polycrystalline CuSb1-xGaxTe2 alloys with the nominal composition of x = 0.01, x = 0.05, x = 0.15. The samples were synthesized by the two-step process as follows melting and quenching, Ball milling and spark plasma sintering. The presence of various scattering mechanisms such as point defect scattering, alloy scattering and Umklapp scattering significantly reduced the lattice thermal conductivity of 0.56 W/mK at 453 K. The improved power factor of 0.396 mW/mK(2) attained due to the highest weighted mobility of 81.04 cm(2)/Vs for x = 0.01 sample.