Thermal Interaction of Graphene with Metals

Kumar许多通信和军事电子产品都需要能在100 GHz到THz频率范围内工作的场效应管。石墨烯是已知的最薄、最坚固的材料之一，具有特殊的电子和热性能。基于石墨烯的晶体管可以超过现有晶体管的性能，这使得它们成为下一代高频器件的非常有吸引力的替代品。石墨烯通常与其设备中的金属和绝缘体相互作用，这显着改变了其性质。基于石墨烯的器件的性能可能受到金属-石墨烯界面处接触特性的限制。了解石墨烯与其设备中连接的金属之间的电子和热相互作用已成为当务之急。金属-石墨烯界面的热输运和电输运强烈依赖于界面化学键的结构和性质。为了准确地模拟石墨烯器件的性能，并在可能的情况下设计界面，破译金属-石墨烯界面上的耦合电子-热输运是很重要的。本研究的目的是开发和使用系统的模拟和实验技术，考虑金属-石墨烯界面的成键和结构，以研究界面的电热输运，并阐明与纳米级石墨烯晶体管相关的时间和长度尺度上界面电/热接触电阻的关键成分。将进行基于第一性原理的研究，以将界面热特性与化学键的性质和界面结构相关联。将制作金属-石墨烯界面结构，并对其进行表征，并测量热阻/电阻。这项研究将导致对传输的新理解的发展，为以前所未有的精度对下一代石墨烯设备，特别是高频和高功率设备的性能进行建模奠定了框架。通过本研究对金属-石墨烯接触界面输运的理解，将为石墨烯晶体管的有效热管理提供方向，使其能够在很高的频率范围内工作或在较低的温度下工作。这一成就将显著提高石墨烯晶体管的能力，降低这些器件在高频电子应用中使用的关键障碍，同时显著提高未来电子系统的能效、性能和运行寿命。该项目将为研究生和本科生开发计算建模和能源运输领域的教材。本研究准备的小型演示和讲座将提高K-12学生对能源相关问题的认识，并激励他们接受大学和研究生教育。

1236416KumarMany communication and military electronics require field - effect transistors which can operate in the frequency range of 100s of GHz to THz. Graphene is one of the thinnest and strongest known materials with exceptional electronic and thermal properties. The graphene based transistors can exceed the performance of existing transistors which makes them very attractive alternative for next generation high frequency devices. Graphene typically interacts with metals and insulators in its devices which significantly changes its properties. The performance of graphene based devices can be limited by the characteristics of the contact at the metal-graphene interface. It has become imperative to understand the electronic and thermal interaction between graphene and the metals it interfaces in its devices. The thermal and electrical transport across the metal-graphene interfaces is strongly dependent on the structure and nature of the chemical bond at the interface. It is important to decipher the coupled electronic-thermal transport at metal-graphene interfaces as a function of interfacial configuration in order to accurately model the performance of graphene devices and engineer the interfaces when possible. The objective of this research is to develop and employ systematic modeling and experimental techniques that consider the bonding and structure at metal-graphene interfaces in order to investigate the interfacial electrical-thermal transport and elucidate the crucial components of interfacial electrical/thermal contact resistances at time and length scales relevant to nanoscale graphene transistors. A first-principles-based study will be performed to correlate the interfacial thermal characteristics to the nature of chemical bonding and interfacial structure. Metal-graphene interface structures will be fabricated, characterized and thermal/electrical resistances will be measured. This research will lead to development of a new understanding of transport that sets the framework for modeling the performance of next-generation graphene devices with unprecedented accuracy, especially high-frequency and high-power devices. The understanding of interfacial transport at metal-graphene contact developed by this research will provide directions for efficient thermal management of graphene transistors which will allow them to operate in very high frequency regimes or operate the device at lower temperatures. Such achievement will significantly enhance the capabilities of graphene transistors and reduce a critical barrier for use of these devices in high frequency electronics applications while leading to a significant gain in the energy efficiency, performance, and operating life of future electronic systems. The project will lead to the development of educational materials in the area of Computational Modeling and Energy Transport for both graduate and undergraduate students. Small demonstrations and lectures prepared by this research will increase the awareness of K-12 students for energy related problems and also motivate them for college and graduate education.