Rediscover δ₅ boron sheet: Interaction with Ni substrate and MoS₂ monolayer

By using the particle swarm optimization algorithm combined with first-principles methods, we report the prediction of a stable structure of two-dimensional (2D) boron monolayer (δ₅ sheet) with P6/M space group and 6 atoms in the unit cell that can be grown on a Ni (111) surface. The metallic nature of the δ₅ sheet is proved by the calculated band structure and density of states. Its dynamical and thermal stabilities are confirmed by the phonon spectrum and ab initio molecular dynamics simulation. We find that the Ni substrate stabilizes the δ₅ sheet by the electron transfer between them and chemical hybridization at the B-Ni interface. The properties of both δ₅ sheet and MoS₂ monolayer are preserved in the combined heterostructure, indicating that the δ₅ sheet can be used as an electrode material for future nanodevices.