| 초록 |
Developing strategies allowing for strong phonon scattering and high carrier mobility at the same time is a primary task in thermoelectrics. In this presentation, we discuss the rational design of high performance thermoelectric system of Pb0.95Sb0.033Se1-yTey (y=0–0.4) by incorporating unique defect architecture. We integrate multiple defects that include point defects, vacancy-driven dense dislocations, and Te-induced nanoprecipitates. They give rise to an ultralow lattice thermal conductivity of ~0.4 Wm-1K-1, closing to the theoretical lower limit. Remarkably, Te alloying increases a density of nanoprecipitates that affect mobility negligibly and disrupt phonon transport significantly. It also ceases the growth of dislocations that scatter both electrons and phonons heavily. As a consequence, Pb0.95Sb0.033Se0.6Te0.4 exhibits the highest ZT ~1.5 at 823 K. These results highlight the potential of defect engineering to control electrical and thermal transport properties independently. |
