Transport properties of carbon-nanotube devices studied by tight-binding and ab-initio calculations

通过紧束缚和从头计算研究碳纳米管器件的输运特性

• 批准号: 5323326
• 负责人: Professor Dr. Stefan Heinze
• 金额: --
• 依托单位: Arbeitsgruppe Theoretical Nanoscience und Spintronics
• 依托单位国家: 德国
• 项目类别: Emmy Noether International Fellowships
• 财政年份: 2001
• 资助国家: 德国
• 起止时间: 2000-12-31 至 2003-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/5323326?language=en
• 关键词: Transport; properties; carbon; nanotube; devices

In the near future, the scaling down of semiconductor devices to smaller and smaller sizes will reach fundamental limits (~ 50 nm) below which the devices become inoperable. On the other hand, the discovery of carbon nanotubes in 1991 with their remarkable electronic, structural, mechanical and conductive properties has opened the door to build nanodevices from these large molecules with sizes below the limits for common semiconductor devices. Depending on their chirality carbon nanotubes show metallic as well as semiconducting properties. By contacting such nanotubes to metal leads or even contacting different nanotubes, devices like field-effect transistors, single electron transistors, or rectifiers have been created. However, there are still a number of serious problems to be solved. For example contact resistances between the metal leads and the nanotubes are still too large for the desired application as fast devices with low power dissipation. Little is known about the responsible effects and theoretical effort seems necessary to gain more insight. Other open questions concern the conduction in nanotube junctions, the resistance of nanotubes, electromigration as well as the operation and control of devices by external fields. In this project we intend to tackle some of these problems using tight-binding as well as ab-initio calculations. While the semi-empirical tight-binding calculations will allow large-scale systems and reveal the main underlying physical principles they may be insufficiently accurate in details. Therefore, we intend to perform ab-initio calculations in the second stage of this project.

在不久的将来，将半导体设备缩小到越来越小的尺寸将达到基本限制（〜50 nm），在该限制下，设备将无法操作。另一方面，1991年碳纳米管的发现具有出色的电子，结构，机械和导电性能，已经为这些大分子构建了纳米版本的大门，其尺寸低于公共半导体设备的极限。取决于其手性碳纳米管显示金属和半导体特性。通过将这种纳米管接触到金属导线，甚至与不同的纳米管接触，已经创建了诸如现场效应晶体管，单电子晶体管或整流器之类的设备。但是，仍然有许多严重的问题要解决。例如，金属导线和纳米管之间的接触电阻仍然太大，对于所需的应用，作为具有低功率耗散的快速设备。对负责任的效果知之甚少，理论上的努力似乎是获得更多洞察力的必要条件。其他开放的问题涉及纳米管连接，纳米管的阻力，电气移民以及外部磁场对设备的操作和控制的传导。在这个项目中，我们打算使用紧密结合以及AB-Initio计算来解决其中一些问题。尽管半经验的紧密结合计算将允许大规模系统，并揭示主要的基本物理原理，它们的细节可能不足以准确。因此，我们打算在该项目的第二阶段执行AB-Initio计算。