Yang Yang, Zhou Yuhao, Luo Zhuang, Guo Yandong, Rao Dewei, Yan Xiaohong
School of Materials Science and Engineering, Jiangsu University, Zhenjiang 212013, China.
Phys Chem Chem Phys. 2019 May 8;21(18):9296-9301. doi: 10.1039/c9cp00427k.
The electronic structures of phosphorene-like SnS/SnSe nanoribbons and the transport properties of a SnS-SnSe nanoribbon lateral heterostructure are investigated by using first-principles calculations combined with nonequilibrium Green's function (NEGF) theory. It is demonstrated that SnS and SnSe nanoribbons with armchair edges (A-SnSNRs and A-SnSeNRs) are semiconductors, independent of the width of the ribbon. Their bandgaps have an indirect-to-direct transition, which varies with the ribbon width. In contrast, Z-SnSNRs and Z-SnSeNRs are metals. The transmission gap of armchair SnSNR-SnSeNR is different from the potential barrier of SnSNR and SnSeNR. The I-V curves of zigzag SnSNR-SnSeNR exhibit a negative differential resistive (NDR) effect due to the bias-dependent transmission in the voltage window and are independent of the ribbon width. However, for armchair SnSNR-SnSeNR, which has a low current under low biases, it is only about 10-6 μA. All the results suggest that phosphorene-like MX (M = Sn/Ge, X = S/Se) materials are promising candidates for next-generation nanodevices.
通过结合非平衡格林函数（NEGF）理论的第一性原理计算，研究了类黑磷的SnS/SnSe纳米带的电子结构以及SnS-SnSe纳米带横向异质结构的输运性质。结果表明，具有扶手椅边缘的SnS和SnSe纳米带（A-SnSNRs和A-SnSeNRs）是半导体，与纳米带宽度无关。它们的带隙具有从间接带隙到直接带隙的转变，且随纳米带宽度而变化。相比之下，Z-SnSNRs和Z-SnSeNRs是金属。扶手椅型SnSNR-SnSeNR的传输间隙不同于SnSNR和SnSeNR的势垒。锯齿形SnSNR-SnSeNR的I-V曲线由于电压窗口中与偏置相关的传输而呈现负微分电阻（NDR）效应，且与纳米带宽度无关。然而，对于在低偏置下电流较低的扶手椅型SnSNR-SnSeNR，其电流仅约为10-6μA。所有结果表明，类黑磷的MX（M = Sn/Ge，X = S/Se）材料是下一代纳米器件的有前途的候选材料。
