Rectifying Performance of Heterojunction Based on α-Borophene Nanoribbons with Edge Passivation.

We propose a planar model heterojunction based on α-borophene nanoribbons and study its electronic transport properties. We respectively consider three types of heterojunctions. 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). 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. Specifically, the rectification ratio of the junction is almost unchanged when its left metallic ribbon changes from ZBNR to 1H-Z αBNR. However, its ratio increases from 120 to 240 when the right semiconducting one varies from 2H-Z αBNR to N-Z αBNR. This rectification effect can be explained microscopically by the matching degree the electronic bands between two parts of a junction. Our findings imply that the borophene-based heterojunctions may have potential applications in rectification nano-devices.

我们提出了一种基于α-硼烯纳米带的平面模型异质结，并研究了其电子输运性质。我们分别考虑了三种类型的异质结。每种类型由两条锯齿形边缘的α-硼烯纳米带（Z αBNR）组成，一条是边缘未被钝化或被一个氢原子钝化的金属性纳米带（1H - Z αBNR），另一条是边缘被两个氢原子（2H - Z αBNR）或一个氮原子（N - Z αBNR）钝化的半导体性纳米带。利用第一性原理计算结合非平衡格林函数，我们发现整流性能在很大程度上取决于结的原子结构细节。具体而言，当左侧金属性纳米带从ZBNR变为1H - Z αBNR时，结的整流比几乎不变。然而，当右侧半导体性纳米带从2H - Z αBNR变为N - Z αBNR时，其整流比从120增加到240。这种整流效应可以从微观上通过结的两部分之间电子能带的匹配程度来解释。我们的研究结果表明，基于硼烯的异质结在整流纳米器件中可能具有潜在应用。