One-dimensional phosphorus chain and two-dimensional blue phosphorene grown on Au(111) by molecular-beam epitaxy

Single-layer (SL) phosphorus (phosphorene) has drawn considerable research attention recently as a new two-dimensional (2D) material with great application promises. Blue phosphorus (blueP), an allotrope of black phosphorus, has been suggested to exist in the SL form on some substrates. Here, we report the growth of blueP by molecular-beam epitaxy and reveal an explicit sequential growth behavior that involves a dewetting process of the first adsorbed P atoms in the (root 3 x root 3) R30 degrees. patches for the nucleation and growth of SL blueP-like islands. We also reveal a one-dimensional (1D) chain structure at low coverage. Interestingly, over a large coverage range, a composite surface containing locally high-P coverage blueP islands surrounded by locally low-coverage 1D chains prevails over the homogeneous (root 3 x root 3)R30 degrees. or P-trimer covered surfaces. Such a phase-separated composite surface is found to be favorable from an energy-minimization point of view and can be general for the growth of other systems.