Room-temperature pressure-induced nanostructural CuInTe₂ thermoelectric material with low thermal conductivity

A room-temperature high-pressure synthesis method is proposed as an alternative way to induce nanoscale structural disorder in the bulk thermoelectric CuInTe₂ matrix. This disorder stems from the coexistence of distinct domains with different degrees and geometries of disorder at Cu/In cation sites. The lattice thermal conductivity of high-pressure-treated CuInTe₂ is substantially less than that of hot-pressed CuInTe₂. The Debye-Callaway model reveals that the reduced lattice thermal conductivity is mainly attributed to disorder at the Cu/In cation sites and stacking faults, which were probably created during formation of the high-pressure-treated phases. This study demonstrates that room-temperature high-pressure synthesis can produce a radical change in the crystal structure and physical properties of conventional thermoelectric materials.