First‐Principles Investigations on the Impact of Shear Deformation on the Photoelectric Characteristics of <scp>SnSeS</scp> Systems

ABSTRACT Utilizing first‐principles computations grounded in density functional theory (DFT), this study systematically investigates the modulation mechanism of shear deformation on the stability, optical properties, and electronic characteristics of the SnSeS structure. The SnSeS system exhibits characteristics of an indirect bandgap semiconductor, as determined by first‐principles calculations. Under shear strain, the bandgap gradually decreases from 1.112 to 0 eV, transitioning from a semiconductor to a metal, which enhances the conductivity of the SnSeS system. Optical characterization reveals that applying shear strain induces a blueshift in the low‐energy absorption and reflection spectra of the SnSeS system, accompanied by a concurrent enhancement in both optical reflectance and absorbance as strain intensity increases. Furthermore, shear deformation effectively enhances the electronic transition capability of this system and significantly reduces the energy loss in the high‐energy region. The findings demonstrate how shear strain can precisely tailor the optical and electronic attributes of Janus SnSeS, offering critical insights for the development of strain‐responsive optoelectronic systems.