RUI: Ultrafast Conductivity Measurements of Graphene Films

RUI：石墨烯薄膜的超快电导率测量

• 批准号: 1006065
• 负责人: James Heyman
• 金额: $ 24万
• 依托单位: Macalester College
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-09-01 至 2013-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1006065&HistoricalAwards=false
• 关键词: RUI; Ultrafast; Conductivity; Measurements; Graphene

****NON-TECHNICAL ABSTRACT****Graphene is a novel carbon material consisting of one-atom thick sheets of carbon. Discovered in 2004, this material holds great promise for electronic applications ranging from transparent conducting films (used in solar cells) to ultra-high-speed transistors. This individual investigator award supports a research project at a predominately undergraduate institution that will investigate how rapidly the conductivity of graphene can be varied, which is relevant to the development of high-speed graphene-based electronics. It is expected that the conductivity of graphene can change on very fast timescales. To investigate the fast change in conductivity, the graphene sample will be excited with an ultra-short pulse of light and subsequently the resulting change in conductivity will be measured with an ultra-short pulse of terahertz radiation. Conductivity measurements under a range of conditions will enable the isolation of the fundamental processes, which control the electronic properties of graphene. This research will also serve to train undergraduate science students in Photonics and experimental Condensed Matter Physics. During the past 15 years, the investigator's laboratory has trained 35 advanced undergraduates, more than two thirds of whom have pursued graduate degrees in Science, Mathematics or Engineering.****TECHNICAL ABSTRACT****Graphene shows exceptional promise as an electronic material for nanoscale transistors and high-speed electronics. This individual investigator award supports a project that will study carrier dynamics in graphene and ultra-thin graphite using time-resolved THz spectroscopy. Conducting films of graphene flakes can now be easily produced from graphene oxide and from graphene solutions. Time resolved THz and infrared spectroscopy are well-suited tools for studying the electronic properties of these flakes. These measurements use an optical or infrared pump pulse to excite a sample and a delayed THz pulse to probe the resulting transient change in conductivity. The research is expected to determine the electron and hole scattering rates, lifetimes and mobilities in graphene flakes formed by mechanical or chemical exfoliation of graphite. In this way the measurements will help probe the suitability of these materials for a variety of applications from transparent conducting films to transistors. The research program will also provide education and research training opportunities for advanced undergraduate students. During the past 15 years, the investigator's laboratory has trained 35 advanced undergraduates, more than two thirds of whom have pursued graduate degrees in Science, Mathematics or Engineering.

* 非技术摘要 * 石墨烯是一种由单原子厚的碳片组成的新型碳材料。 这种材料于2004年被发现，在从透明导电膜（用于太阳能电池）到超高速晶体管的电子应用中具有巨大的潜力。 这个个人研究者奖支持一个主要的本科院校的研究项目，该项目将研究石墨烯的导电性如何快速变化，这与高速石墨烯电子产品的发展有关。 预计石墨烯的导电性可以在非常快的时间尺度上变化。 为了研究电导率的快速变化，石墨烯样品将用超短光脉冲激发，随后将用超短太赫兹辐射脉冲测量电导率的变化。 在一系列条件下的电导率测量将能够隔离控制石墨烯电子特性的基本过程。 这项研究也将有助于培养本科理科学生在光子学和实验凝聚态物理。 在过去15年中，调查员的实验室培养了35名高年级大学生，其中三分之二以上是攻读科学、数学或工程学研究生学位。石墨烯作为纳米晶体管和高速电子产品的电子材料显示出非凡的前景。 这个个人研究者奖支持一个项目，该项目将使用时间分辨太赫兹光谱研究石墨烯和超薄石墨中的载流子动力学。 石墨烯薄片的导电膜现在可以很容易地由氧化石墨烯和石墨烯溶液生产。 时间分辨太赫兹和红外光谱是研究这些薄片的电子特性的非常合适的工具。这些测量使用光学或红外泵浦脉冲来激发样品，并使用延迟的THz脉冲来探测电导率的瞬态变化。 该研究预计将确定通过石墨的机械或化学剥离形成的石墨烯薄片中的电子和空穴散射率、寿命和迁移率。 通过这种方式，测量将有助于探测这些材料对从透明导电膜到晶体管的各种应用的适用性。 该研究计划还将为高级本科生提供教育和研究培训机会。在过去的15年中，研究员的实验室培养了35名高级本科生，其中三分之二以上的人攻读了科学、数学或工程学的研究生学位。