Piezoelectric engineering boosts thermoelectric performance of GeTe via local electric field and phonon scattering

Grain boundaries or phase boundaries, which play a pivotal role in decoupling electrical and thermal transport, are frequently engineered to regulate thermoelectric performance. Although extensive research has been conducted on their composition, density, coherency, and width, relatively limited attention has been paid to the strategic utilization of local electric fields at these interfaces for manipulating charge carrier and phonon transport. By incorporating piezoelectric material Pb(Zr 0.50 Ti 0.44 Fe 0.06 )O 3 into thermoelectric material Ge 0.94 Sb 0.06 Te, a local electric field is generated that effectively impedes the transport of low-energy holes. This innovative approach results in a noteworthy enhancement of the Seebeck coefficients in the composites without compromising electrical conductivity. Consequently, an improvement in zT values can be achieved for the sample Ge 0.94 Sb 0.06 Te+ 0.3 wt% Pb(Zr 0.50 Ti 0.44 Fe 0.06 )O 3 , showing a 15 % increase compared to the sample without Pb(Zr 0.50 Ti 0.44 Fe 0.06 )O 3 . Simulation results further corroborate the practical significance of this approach, predicting an impressive conversion efficiency of 10.7 % for a single-leg thermoelectric device, thereby underscoring its considerable potential for power generation applications.