▎ 摘　　要

Penta-graphene, a two-dimensional (2D) metastable carbon allotrope, has been proposed by composing entirely of carbon pentagons. In this work, we have proposed heterojunctions composed of penta-graphene nanoribbons (penta-GNRs) and penta-B2N4 nanoribbons, the different edge states: bare, H or Cl atoms passivation is considered, respectively. Using the spin-polarized density functional theory (DFT) and the non-equilibrium Green's function (NEGF) method, the band structures and electronic transport properties of the heterojunctions have been calculated. Our results show that an indirect band gap appears in the band structures of the penta-GNRs, and that a metal property occurs in the penta-B2N4 nanoribbons. The spin-splitting, spin-filtering and negative differential resistance (NDR) effects are occurred in the heterojunction with bare edges. We also find that the unidirectional conductivity occurs in the heterojunction with H atoms passivation. And the bipolar spin-filtering effect can be observed in the heterojunction with Cl atoms passivation.