Design of Atomically Precise Nanoscale Negative Differential Resistance Devices
Design of Atomically Precise Nanoscale Negative Differential Resistance Devices
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DOI：
10.1002/adts.201800172
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发表时间：
2018-10
影响因子：
3.3
通讯作者：
Zhongcan Xiao;Chuanxu Ma;Jingsong Huang;L. Liang;Wenchang Lu;K. Hong;B. Sumpter;An‐Ping Li;J. Bernholc
中科院分区：
文献类型：
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作者：
Zhongcan Xiao;Chuanxu Ma;Jingsong Huang;L. Liang;Wenchang Lu;K. Hong;B. Sumpter;An‐Ping Li;J. Bernholc
将器件尺寸缩小到纳米范围对传统器件设计提出了重大挑战，这是因为跨纳米尺寸的潜在电流泄漏，以及在处理原子级组件时需要保持重复性。在这里，我们研究了基于原子精密石墨烯纳米带的负微分电阻(NDR)器件。对传统的双势垒共振隧穿二极管NDR结构的计算评估揭示了原子尺度上的重要问题，涉及在获得高峰值电流的同时最小化引线之间的隧道电流的需要。提出了一种新的器件结构，该结构由多个短段组成，通过段间电子能级的对准来实现高电流，同时增大引线之间的隧道距离。在扶手椅纳米带合成的中间阶段，可以使用扫描隧道显微镜(STM)针尖以原子精度构建所提出的结构。文中还给出了界面能带排列的实验评价和器件有源部分的STM图像。这种理论和实验相结合的方法为设计具有原子精度的纳米级器件开辟了一条新的途径。
Downscaling device dimensions to the nanometer range raises significant challenges to traditional device design, due to potential current leakage across nanoscale dimensions and the need to maintain reproducibility while dealing with atomic‐scale components. Here, negative differential resistance (NDR) devices based on atomically precise graphene nanoribbons are investigated. The computational evaluation of the traditional double‐barrier resonant‐tunneling diode NDR structure uncovers important issues at the atomic scale, concerning the need to minimize the tunneling current between the leads while achieving high peak current. A new device structure consisting of multiple short segments that enables high current by the alignment of electronic levels across the segments while enlarging the tunneling distance between the leads is proposed. The proposed structure can be built with atomic precision using a scanning tunneling microscope (STM) tip during an intermediate stage in the synthesis of an armchair nanoribbon. An experimental evaluation of the band alignment at the interfaces and an STM image of the fabricated active part of the device are also presented. This combined theoretical–experimental approach opens a new avenue for the design of nanoscale devices with atomic precision.