Decoupling thermoelectric parameters by the energy-dependent carrier and phonon scattering based on the nano-structuring interface design

Thermoelectric materials can transfer heat energy to electricity energy or vice versa. However, the transfer efficiency is restricted by the interdependent thermoelectric parameters. In this work, all the thermoelectric parameters are simultaneously optimized via the energy-dependent carrier and phonon scattering based on the nano-structuring interface design. As a result, not only the electrical conductivity is significantly enhanced by increasing the electron concentration, the Seebeck coefficient is maintained in a high value due to the energy-dependent carrier scattering mechanism. Otherwise, based on the stronger phonon scattering by the nanoinclusions and dislocations, the lattice thermal conductivity is markedly suppressed. And thus, a peak ZT=1.5 and an outstanding conversion efficiency eta=9 % are achieved for Pb0.995Bi0.005Te/0.1 wt.%Fe3O4 composite, indicating that the thermoelectric property of n-type PbTe can be elevated greatly by embedding Fe3O4 nanoinclusions. This strategy of nano-structuring interface design can also be highly applicable in improving the performance of other state-of-the-art thermoelectric materials.