The large contact resistance is an insurmountable problem for the Schottky contact between the semiconducting two-dimensional channel material and the metal electrode. One solution to the Schottky contact issue is to decrease the contact resistance. Here, by using the first-principles calculations combined with the non-equilibrium Green’s function technique, we find that when monolayer arsenene is covalently bonded with chlorine adatoms, it can transform from the intrinsic semiconductor to metal, which greatly improves its conductivity. Moreover, in the double-layer structure, the Cl adatoms can hop from one layer to the other by applying a vertical electric field. Their interlayer translation can turn arsenene and metallic electrodes from Schottky contact to Ohmic contact, then the resistance is greatly reduced, producing significant switching effects. The highest on/off ratio is as large as 638 at zero bias voltage, which can be utilized as nonvolatile high-density memory and logic operation devices based on arsenene homojunction.

对于半导体二维沟道材料和金属电极之间的肖特基接触而言，大的接触电阻是不可克服的问题。解决肖特基接触问题的一种方法是降低接触电阻。在这里，通过使用第一性原理计算结合非平衡格林函数技术，我们发现，当单层砷与氯原子共价键合时，它可以从本征半导体转变为金属，从而大大提高了其导电性。而且，在双层结构中，通过施加垂直电场，Cl原子可以从一层跳到另一层。它们的层间平移可使砷和金属电极从肖特基接触变为欧姆接触，从而大大降低了电阻，产生明显的开关效果。在零偏置电压下，最高的开/关比高达638，可将其用作基于砷同质结的非易失性高密度存储器和逻辑运算器件。