Pressure-dependent optoelectronic properties of TlInS2 crystals (II): Insights from DFT simulations

Abstract

This study investigates the structural and optical properties of TlInS₂ crystals under elevated pressures using density functional theory (DFT). The dielectric function shows significant shifts under pressure, indicating changes in electronic transitions and band structures. Analysis of the refractive index reveals pressure-induced spectral peaks and a semiconductor-to-metal transition at 6.25 GPa. Reflectivity measurements show an increase with pressure, reaching 0.504 at 10 GPa, suggesting enhanced optical properties. Optical conductivity analysis shows increased total conductivity with pressure due to reduced band gap energy, stimulating exciton formation and metallic behavior beyond 6.25 GPa. These comprehensive insights into the pressure-dependent behaviors of TlInS₂ are essential for potential applications in electronic and optoelectronic devices.