Tunable electronic and optical properties in buckling a non-lamellar BS monolayer

We propose a novel polymorph of a hexagonal B 3 S monolayer by combing structure swarm intelligence and first-principles calculations. Phonon spectrum analysis and ab initio molecular dynamics simulation indicate that the new structure is dynamically and thermally stable. Furthermore, the structure is mechanically stable and has a satisfactory elastic modulus. Our results show that the B 3 S monolayer is a semiconductor with strong visible-light optical absorption. More importantly, the electronic properties of the structure are tunable via surface functionalization. For example, hydrogenation or fluorination could transform the monolayer from the semiconducting to metallic state. On the other hand, surface oxidation could significantly enhance both carrier mobility and near-infrared optical absorption. Furthermore, we also discovered that the monolayer possesses satisfactory storage capacity for H 2 . A previously unknown monolayer (h1-B 3 S) is predicted by the structure swarm intelligence method. The proposed structure possesses high visible and near-infrared light absorption and has satisfactory H 2 storage capacity.