Vicinal metal surfaces as potential catalysts for phosphorene epitaxial growth

Phosphorene, a single layer of black phosphorous (BLK-P), has significant potential for flexible and tunable electronics, but attempts to grow it epitaxially have been unsuccessful to date. Close-packed (111) surfaces of metals favor blue phosphorous (BL-P) over BLK-P due to the hexagonal symmetry of the former. Here, we investigate computationally the alternative offered by stepped substrates. Using the model of a Cu(311) surface, we find that surface steps can favor energetically BLK-P over BL-P. This can be rationalized in terms of surface density of states and orbital hybridization, which leads to a stronger surface bonding of BLK-P. This suggests that vicinal metal surfaces of metals can offer a viable path toward phosphorene synthesis.