Structure of Blue Phosphorus Grown on Au(111) Surface Revisited

Blue phosphorus (BlueP) is predicted as a new two-dimensional allotrope of black phosphorus with a great potential in electronic device applications. Recently, the growth of BlueP on Au(1 1 1) surface has been demonstrated by several groups. However, there is still a controversy surrounding the exact structure of BlueP on Au(1 1 1). Herein, by combining the stochastic surface walking (SSW) global optimization algorithm and a neural network potential, we successfully identify the structure model of BlueP on Au(1 1 1), which is consistent with all recent experimental observations. It turns out that what has been grown on Au(1 1 1) in recent experiments is a single-layer structure composed of Au atom-connected BlueP fragments. As a substrate to grow BlueP, the Au(1 1 1) surface suffers from the too strong Au-P interaction. Possible ways to grow continuous single layer BlueP are suggested.