Oscar Ruiz-Cigarrillo

Linear optical response of monolayer \(\mathrm{Sb_2Te_3}\) under uniaxial strain assessed by Time-Dependent Density Functional Theory

Abstract: Strain engineering enables control over the optical properties of 2D materials, but systematic theoretical studies are computationally demanding. By using Time-Dependent Density Functional Theory (TDDFT) with optimized hybrid functionals (B3LYP and Gau-PBE) and a long-range corrected kernel (LRC), we study strain-tunable optical properties in monolayer \(\mathrm{Sb_2Te_3}\). Uniaxial tensile strain along the \(x\)-direction induces optical anisotropy between in-plane components and modified near-infrared absorption. Both functionals yield consistent results for 0-5% strain, validating our predictions. The TDDFT-LRC approach captures the essential physics, validating through this comparison with more robust reference calculations. Strain-induced anisotropy with \(\varepsilon_{xx}/\varepsilon_{yy}\) ratios of 1.4-3 eV suggests applications in polarization-sensitive photodetectors and strain sensors. This work presents a computational framework for strain-engineered optical properties in \(\mathrm{Sb_2Te_3}\) and related chalcogenides, helping in the development of next-generation optoelectronic devices where mechanical deformation modulates optical response.