Regular Arrangement of Two-Dimensional Clusters of Blue Phosphorene on Ag(111)

Two-dimensional (2D) blue phosphorene with a honeycomb structure is the phosphorus analog of graphene, and is regarded as a promising 2D material with a large tunable band gap and high charge-carrier mobility. Here, using the molecular beam epitaxy method, we synthesize monolayer blue phosphorene on the Ag(111) surface. Combined with first-principles calculations, scanning tunneling microscopy measurements reveal that the blue phosphorene on the Ag(111) surface consists of 2D clusters with a buckling 1 x 1 lattice, arranged regularly on the Ag(111). The formation of these phosphorus clusters stems from the strain modulation induced by the lattice mismatch between blue phosphorene and the Ag(111) substrate. Moreover, x-ray photoelectron spectroscopy measurements are performed to study the instability of the blue phosphorene clusters in air. The realization of regular nanoclusters of blue phosphorene with unique sizes and morphology provides an ideal platform for the exploration of the quantum physical properties and applications of blue phosphorene.