Immunity of electronic and transport properties of phosphorene nanoribbons to edge defects
phosphorene nanoribbons, atomistic quantumtransport simulation, edge defects, transport gap, mean free path, electron and hole mobility
We present an extensive study of the electronic properties and carrier transportin phosphorene nanoribbons (PNRs) with edge defects by using rigorousatomistic quantum transport simulations. This study reports on the size- anddefect-dependent scaling laws governing the transport gap, and the mean freepath and carrier mobility in the PNRs of interest for future nanoelectronicsapplications. Our results indicate that PNRs with armchair edges (aPNRs) aremore immune to defects than zig-zag PNRs (zPNRs), while both PNR typesexhibit superior immunity to defects relative to graphene nanoribbons (GNRs).An investigation of the mean free path demonstrated that even in the case of alow defect density the transport in PNRs is diffusive, and the carrier mobilityremains a meaningful transport parameter even in ultra-small PNRs. We foundthat the electron–hole mobility asymmetry (present in large-area phosphorene)is retained only in zPNRs for W > 4 nm, while in other cases the asymmetry issmoothed out by edge defect scattering. Furthermore, we showed that aPNRsoutperform both zPNRs and GNRs in terms of carrier mobility, and that PNRsgenerally offer a superior mobility-bandgap trade-off, relative to GNRs andmonolayer MoS2. This work identifies PNRs as a promising material for theextremely scaled transistor channels in future post-silicon electronic technology,and presents a persuasive argument for experimental work on nanostructuredphosphorene.
Tsinghua University Press
Mirko Poljak,Tomislav Suligoj, Immunity of electronic and transport properties of phosphorene nanoribbons to edge defects. NanoRes.2016, 9(6): 1723–1734