Metal chalcogenides especially Cu2-x Se has gained much attention in thermoelectric community due to its complex crystal structure and superionic behavior. Here, we report a facile method to improve the thermoelectric...Metal chalcogenides especially Cu2-x Se has gained much attention in thermoelectric community due to its complex crystal structure and superionic behavior. Here, we report a facile method to improve the thermoelectric efficiency by introducing Zn Te nanoinclusions into the matrix of Cu2-x Se. As a result, a substantial improvement of 32% in electrical conductivity of Cu2-x Se-Zn Te composite is observed. The increase in electrical conductivity is at the expense of Seebeck coefficient, which slightly decreases the power factor of the composite samples than that of pure Cu2-x Se. Furthermore, the introduction of secondary phase facilitates in declining the total thermal conductivity of Cu2-x Se-Zn Te composite up to 34% by suppressing the lattice thermal contributions. Thus, the moderate power factor and lower thermal conductivity values result in an improved figure of merit(z T) value of ~0.40 in mid-range temperature(750 K) for Cu2-x Se-Zn Te composite with 10 wt.% of Zn Te, which is about 40% higher than that of its pure counterpart. Hence, it is believed that the incorporation of Zn Te nanoinclusions in the matrix of Cu2-x Se may be an important route to improve the thermoelectric properties of Cu2-x Se based compounds.展开更多
文摘Metal chalcogenides especially Cu2-x Se has gained much attention in thermoelectric community due to its complex crystal structure and superionic behavior. Here, we report a facile method to improve the thermoelectric efficiency by introducing Zn Te nanoinclusions into the matrix of Cu2-x Se. As a result, a substantial improvement of 32% in electrical conductivity of Cu2-x Se-Zn Te composite is observed. The increase in electrical conductivity is at the expense of Seebeck coefficient, which slightly decreases the power factor of the composite samples than that of pure Cu2-x Se. Furthermore, the introduction of secondary phase facilitates in declining the total thermal conductivity of Cu2-x Se-Zn Te composite up to 34% by suppressing the lattice thermal contributions. Thus, the moderate power factor and lower thermal conductivity values result in an improved figure of merit(z T) value of ~0.40 in mid-range temperature(750 K) for Cu2-x Se-Zn Te composite with 10 wt.% of Zn Te, which is about 40% higher than that of its pure counterpart. Hence, it is believed that the incorporation of Zn Te nanoinclusions in the matrix of Cu2-x Se may be an important route to improve the thermoelectric properties of Cu2-x Se based compounds.
