Contact spacing controls the on-current for all-carbon field effect transistors
Contact spacing controls the on-current for all-carbon field effect transistors
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DOI：
10.1038/s42005-021-00747-5
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发表时间：
2021-11-18
影响因子：
5.5
通讯作者：
Fediai, Artem
中科院分区：
文献类型：
--
作者：
Ozdemir, Ali Deniz;Barua, Pramit;Fediai, Artem
结合碳纳米管和石墨烯的全碳场效应晶体管在数字逻辑器件和单光子发射器等许多应用中都有很大的前景。然而，对于碳纳米管/石墨烯混合系统在这类器件中的物理性质的理解仍然有限。在这项结合实验和理论的研究中，我们使用基于石墨烯电极和碳纳米管通道的场效应晶体管的量子输运模型来解释实验观察到的低电流。我们发现大的石墨烯/碳纳米管间距和短的接触长度限制了器件的性能。我们还在本工作中阐明了实验观察到的由平坦的传导带和价带引起的双极性输运行为，并描述了石墨烯和碳纳米管的量子电容对接触和通道区域的非理想栅控制。我们希望我们的见解将加速高效的全碳场效应晶体管的设计。未来设备对缩小尺寸的需求推动了基本硅基组件的极限，因此替代材料，如碳纳米管或石墨烯，正在作为替代品进行研究，但新材料带来了新的挑战。本文从实验和理论两方面研究了全碳晶体管的导通电流，发现触点间距和长度对器件性能有重要影响。
All-carbon field-effect transistors, which combine carbon nanotubes and graphene hold great promise for many applications such as digital logic devices and single-photon emitters. However, the understanding of the physical properties of carbon nanotube (CNT)/graphene hybrid systems in such devices remained limited. In this combined experimental and theoretical study, we use a quantum transport model for field-effect transistors based on graphene electrodes and CNT channels to explain the experimentally observed low on currents. We find that large graphene/CNT spacing and short contact lengths limit the device performance. We have also elucidated in this work the experimentally observed ambipolar transport behavior caused by the flat conduction- and valence-bands and describe non-ideal gate-control of the contacts and channel region by the quantum capacitance of graphene and the carbon nanotube. We hope that our insights will accelerate the design of efficient all-carbon field-effect transistors.The need for reduced dimensions of future devices pushes the limits of essential Si-based components and so alternative materials, such as carbon nanotubes or graphene, are being investigated as alternatives, but with new materials come new challenges. Here, the authors experimentally and theoretically investigate the on-currents for all-carbon transistors finding that contact spacing and length plays an important role in device performance.