We construct three types of in-plane metal-semiconductor lateral junctions. In this work, we investigate the transport properties of heterojunctions made of the zigzag edge Z αBNRs. Hence, the electronic transport property for borophene nanostructures remains to be explored further, although a large number of studies have been carried out on the electronic structures, mechanical and thermal properties. Further, the zigzag edge α-borophene nanoribbon (Z αBNR) exhibits either metallic or semiconducting behavior through different edge modifications. The DFT calculations indicated that the borophene with a “hexagon hole density” ( η) of 1/9, named as α−borophene, is favorable in terms of energy. Theoretical studies point out that the stability of the boron sheet can be increased by introducing a hexagonal hole. So far, a number of 2D boron structures have been obtained by epitaxial growth on Ag (111) substrates, such as β 12-, χ 3-, δ 6-borophene and honeycomb borophene. The theoretical studies predicted that the monolayer boron sheets can be stably existed on the metallic substrate, which was confirmed by the subsequent observations. Recently, borophene monolayers have also received extensive interests after graphene and silicene. These achievements have inspired the effort for further exploring lateral heterojunctions made of more suitable 2D materials. Further, the lateral heterojunctions with atomic thickness have already been prepared in experiments. And some theoretical studies have showed that the lateral heterojunctions have potential applications in field effect transistor and complementary metal oxide semiconductor technologies. Subsequently, the research on lateral heterojunctions based on 2D materials becomes an important topic. Recently, some studies have also shown that 2D materials have broad application prospects in nanoscale thermoelectric devices. Especially, these 2D materials demonstrate some interesting electronic transport behaviors, such as giant magneto resistance (GMR), negative differential resistance (NDR), spin filtering, and rectification, thus having potential applications in nanoscale electronic devices. Over the past decades, a great number of two-dimensional (2D) materials, including graphene, silicene, transition metal dichalcogenides (TMD), and phosphorene, have been extensively studied due to their unique properties. Our findings imply that the borophene-based heterojunctions may have potential applications in rectification nano-devices. This rectification effect can be explained microscopically by the matching degree the electronic bands between two parts of a junction. However, its ratio increases from 120 to 240 when the right semiconducting one varies from 2H-Z αBNR to N-Z αBNR.
Specifically, the rectification ratio of the junction is almost unchanged when its left metallic ribbon changes from ZBNR to 1H-Z αBNR. Using the first-principles calculations combined with the nonequilibrium Green’s function, we observe that the rectifying performance depends strongly on the atomic structural details of a junction. Each type consists of two zigzag-edge α-borophene nanoribbons (Z αBNR), one is metallic with unpassivated or passivated edges by a hydrogen atom (1H-Z αBNR) and the other is semiconducting with the edge passivated by two hydrogen atoms (2H-Z αBNR) or a single nitrogen atom (N-Z αBNR). We respectively consider three types of heterojunctions. We propose a planar model heterojunction based on α-borophene nanoribbons and study its electronic transport properties.