First-principles investigation of the effects of strain on elastic, thermal, and optical properties of CuGaTe₂

Based on the density functional theory, the influences of strain on structural, elastic, thermal and optical properties of CuGaTe₂ are discussed in detail. It is found that the tensile strain on CuGaTe₂ is beneficial to the decrease of lattice thermal conductivity by reducing the mean sound velocity and Debye temperature. Moreover, all strained and unstrained CuGaTe₂ exhibit rather similar optical characters. But the tensile strain improves the ability to absorb sunlight in the visible range. These research findings can give hints for designing thermoelectric and photovoltaic devices.