Thermoelectric properties in nano Y2O3 dispersed Cu2Se

Introducing the nanosecond phase into thermoelectric materials is an effective strategy to improve their thermoelectric properties. In this study, the influence of nano Y2O3 dispersion on the resistivity, Seebeck coefficient and thermal conductivity of Cu2Se + x mol% Y2O3 (x = 0, 0.5, 1.0, 2.0, 3.0) was investigated. Their resistivity and Seebeck coefficient have no obvious change under the combined effects of the microstructure and the energy filtering. Especially, Y2O3 dispersion can inhibit the recrystallization of Cu2Se and make the lamellar grains thinner, thus scattering phonon and reducing the thermal conductivity effectively. When x = 1.0, the thermal conductivity reaches a minimum of 0.65 W/Kmiddotm at 923 K. The dimensionless thermoelectric figure of merit (ZT) value of the Cu2Se + 1.0 mol% Y2O3 sample reaches 1.81 at 923 K. The study indicates that nano rare earth oxides are relatively effective second-phase that can reduce thermal conductivity, which may be further promoted for other thermoelectric materials.

Automated summary

Introducing the nanosecond phase into thermoelectric materials is an effective strategy to improve their thermoelectric properties. In this study, the influence of nano Y2O3 dispersion on the resistivity, Seebeck coefficient, and thermal conductivity of Cu2Se + x mol% Y2O3 was investigated. The results show that the nano Y2O3 dispersion can effectively scatter phonons and reduce thermal conductivity.