Abstract: The rare-earth chalcogenides Y₂Te₃ with low lattice thermal conductivity is a very promising novel thermoelectric material. Applying strain is an effective way to modulate the thermoelectric properties of thermoelectric materials. In this paper, first-principles approach combined with the semiclassical Boltzmann transport theory were used to study the strain modulation of the thermoelectric properties of Y₂Te₃ materials, for which -4% to 4% strain was applied to the Y₂Te₃ materials. The results show that applying compressive strain may modulate thermoelectric properties more effectively than tensile strain. The maximum power factor of p-type Y₂Te₃ increases from 0.4 mW·m^-1·K^-2 to 1.6 mW·m^-1·K^-2 at 300 K, and the maximum power factor of n-type Y₂Te₃ increases from 8 mW·m^-1·K^-2 to 11 mW·m^-1·K^-2 under compressive strain. The maximum thermoelectric figure of merit (ZT) of p-type Y₂Te₃ increases from 0.07 to 0.15 under strain modulation at 300 K, and the maximum ZT of n-type Y₂Te₃ increases from 0.7 to 0.9 under compressive strain. Therefore, n-type Y₂Te₃ has very excellent thermoelectric properties, and the thermoelectric properties of Y₂Te₃ materials can be effectively regulated by applying strain. n-type Y₂Te₃ has great potential as a thermoelectric material.

Key words: thermoelectric material, strain, thermoelectric property, Y₂Te₃, chalcogenide, first-principle