Thermoelectric Properties of CuTe Nanoparticle Incorporated N-Type BiTeSe.

To develop highly efficient thermoelectric materials, the generation of homogeneous heterostructures in a matrix is considered to mitigate the interdependency of the thermoelectric compartments. In this study, CuTe nanoparticles were introduced onto BiTeSe n-type materials and their thermoelectric properties were investigated in terms of the amount of CuTe nanoparticles. A homogeneous dispersion of CuTe nanoparticles was obtained up to 0.4 wt.% CuTe, whereas the CuTe nanoparticles tended to agglomerate with each other at greater than 0.6 wt.% CuTe. The highest power factor was obtained under the optimal dispersion conditions (0.4 wt.% CuTe incorporation), which was considered to originate from the potential barrier on the interface between CuTe and BiTeSe. The CuTe incorporation also reduced the lattice thermal conductivity, and the dimensionless figure of merit was increased to 0.75 at 374 K for 0.4 wt.% CuTe incorporation compared with that of 0.65 at 425 K for pristine BiTeSe. This approach could also be an effective means of controlling the temperature dependence of , which could be modulated against target applications.