The atomic structure of single-crystalline black phosphorus is studied using high-resolution synchrotron-based photoelectron diffraction (XPD). The results show that the topmost phosphorene layer in the black phosphorus is slightly displaced compared to the bulk structure and presents a small contraction in the direction perpendicular to the surface. Furthermore, the XPD results show the presence of a small buckling among the surface atoms, in agreement with previously reported scanning tunneling microscopy results. The contraction of the surface layer added to the presence of the buckling indicates a uniformity in the size of the $s{p}^3$ bonds between P atoms at the surface.

• Received 16 November 2015
• Revised 11 January 2016

DOI:https://doi.org/10.1103/PhysRevB.93.035448