Pressure-mediated band engineering and cation ordering for enhanced thermoelectric performance in CuInTe2 chalcopyrites

The inherent cation disordering and wide bandgap of CuInTe 2 seriously impede carrier concentration optimization, constraining the enhancement of thermoelectric performance. In this work, the inherent cases were addressed by introducing Sb doping and high pressure. Cu Sb bonding was strengthened by incorporating Sb into Te sites, realizing cation ordering while supplying extra hole carriers. Furthermore, with bandgap narrowing induced by applying pressure, the carrier concentration was significantly increased to over ∼10 19  cm −3 , accompanied by optimizing the electronic structure. As a consequence, a high power factor of 1152.4 μWm −1  K −2 at 773 K was achieved. In addition, abundant defect structures were introduced due to Sb doping and external pressure, largely suppressing phonon transport and thus reducing the lattice thermal conductivity to 0.63 Wm −1  K −1 , which approaches the theoretical minimum. Ultimately, a high zT value of 1.14 at 773 K was achieved for CuInTe 1.995 Sb 0.005 prepared under 2.5 GPa. This study demonstrates the efficacy of high pressure and Sb doping in improving the thermoelectric performance of CuInTe 2 , and provides a feasible approach for optimizing cation ordering and band structure in thermoelectrics.