Theoretical investigation on the phase diagram and electronic and optical properties of two-dimensional strained Si6H6 monolayer

Two-dimensional materials exhibit unique properties due to enhanced many-body effects and quantum confinement. In this study, we investigate the dynamic stability, possible synthesis routes, and electronic and optical properties of the hydrogenated two-dimensional Kagome silicene (Si6H6) monolayer using first-principle calculations coupled with the GW-Bethe–Salpeter equations. The Ag(111) substrate is found to be suitable for synthesizing the S-Si6H6 monolayer, which can then be obtained through exfoliation technology. In addition, the S-Si6H6 monolayer is identified as a semiconductor (with an indirect bandgap) and exhibits high hole mobility of 345 cm2 V−1 s−1 and high exciton binding energy of 1.38 eV. Furthermore, the bandgap of S-Si6H6 can be effectively modulated by strain. This work offers theoretical insights into the experimental synthesis of this monolayer and provides a modulation strategy for its optoelectronic applications.