  The electronic transport properties of Janus monolayer black arsenic
phosphorus (b-AsP) nanoribbons have been investigated utilizing the
tight-binding approach. The dependence of electronic structure on edge
structures is systematically investigated. (1,3)nb and (3,1)nb b-AsP
nanoribbons exhibit flatter edge bands than zigzag and armchair counterparts.
The edge band of the armchair ones show double degeneracy. Further, the
calculated results show the band gap of the zigzag ribbon with different
boundary morphology is widely tunable by transverse electric field. A critical
electric field can fully close the gap and induce a phase transition from a
semiconductor into a conductor. Our work suggests dynamically tunable bandgap
in Janus b-AsP nanoribbons and reveals the potential of Janus b-AsP for
transmission devices.
