Materials Research Centre, Indian Institute of Science, Bangalore 560012, India. Centre for Nano Science and Engineering, Indian Institute of Science, Bangalore 560012, India.
Nanotechnology. 2017 Jul 7;28(27):275402. doi: 10.1088/1361-6528/aa75b6.
Due to dimensional confinement of carriers and non-trivial changes in the electronic structure, novel tunable transport properties manifest in nanoscale materials. Here, we report using first-principles density functional theory and non-equilibrium Green's function formalism, the occurrence of negative differential resistance (NDR) in armchair silicene nanoribbons (ASNRs). Interestingly, NDR manifests only in pristine [Formula: see text] ASNRs, where [Formula: see text]. We show that the origin of such a novel transport phenomenon lies in the bias-induced changes in the density of states of this particular family of nanoribbons. With increasing width of the nanoribbons belonging to this family, the peak-to-valley ratios of current decrease due to the increase in the number of sub-bands leading to a reduction in NDR. NDR is possible not only in [Formula: see text] ASNRs, but also in mixed configurations of armchair and zigzag silicene nanoribbons. This universality of NDR along with its unprecedented width-induced tunability can be useful for silicene-based low-power logic and memory applications.
由于载流子的维度限制和电子结构的重要变化，纳米材料表现出新颖的可调谐输运性质。在这里，我们使用第一性原理密度泛函理论和非平衡格林函数形式，报告了在扶手椅硅烯纳米带（ASNR）中出现的负微分电阻（NDR）。有趣的是，NDR 仅在原始 [Formula: see text] ASNR 中表现出来，其中 [Formula: see text]。我们表明，这种新型输运现象的起源在于偏压诱导的这种纳米带族的态密度变化。随着属于这一家族的纳米带宽度的增加，由于子带数量的增加导致 NDR 减小，电流的峰谷比减小。NDR 不仅在 [Formula: see text] ASNR 中是可能的，而且在扶手椅和锯齿形硅烯纳米带的混合构型中也是可能的。这种 NDR 的普遍性以及其前所未有的宽度诱导可调谐性可用于基于硅烯的低功耗逻辑和存储应用。
