Structural Design via Pressure Enables zT > 1 for CuInTe2 Chalcopyrites

Crystalline structures, as the basics of materials, are tightly associated with transport properties. Designing a structure through doping, alloying, and phase engineering to optimize thermoelectric transport properties has always been a crucial strategy in thermoelectrics. In this work, hybrid architectures containing an inherently long-range, nearly cubic framework as well as localized short-range noncubic lattice distortions, are designed in the pristine CuInTe2 chalcopyrites by a unique high-pressure technology. As a result, the long-range order structures motivate degeneracy in electronic bands, markedly improving the electrical transport properties. Meanwhile, suppressed lattice thermal conductivity due to strong phonon scattering is achieved by the short-range disorder structures composed of dense dislocations introduced by pressure. The above incorporation effects lead to a distinguished thermoelectric performance of zT = 1.13 at 773 K for pristine CuInTe2 prepared under 3 GPa. This study demonstrates the bright potential of high pressure as a significant approach in designing bespoke crystalline structures for tuning thermoelectric transport properties.