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****石墨烯是一种新型碳材料，由单原子厚的碳片组成。 这种材料于 2004 年被发现，在从透明导电薄膜（用于太阳能电池）到超高速晶体管等电子应用领域具有广阔的前景。 该个人研究员奖支持一个以本科为主的机构的一个研究项目，该项目将研究石墨烯电导率的变化速度，这与高速石墨烯电子产品的开发相关。 预计石墨烯的电导率可以在非常快的时间尺度上发生变化。 为了研究电导率的快速变化，将用超短光脉冲激发石墨烯样品，随后用太赫兹辐射的超短脉冲测量由此产生的电导率变化。 在一系列条件下进行电导率测量将能够隔离控制石墨烯电子特性的基本过程。 这项研究还将用于培训光子学和实验凝聚态物理方面的本科生。 在过去 15 年里，研究人员的实验室已培养了 35 名高级本科生，其中三分之二以上已攻读科学、数学或工程研究生学位。****技术摘要****石墨烯作为电子材料显示出非凡的前景用于纳米级晶体管和高速电子产品。 该个人研究员奖支持一个项目，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。 现在可以很容易地用氧化石墨烯和石墨烯溶液生产石墨烯薄片导电薄膜。 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，并使用延迟的太赫兹脉冲来探测由此产生的电导率瞬态变化。 该研究预计将确定通过机械或化学剥离石墨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，测量将有助于探索这些材料对于从透明导电薄膜到晶体管的各种应用的适用性。 该研究计划还将为高年级本科生提供教育和研究培训机会。在过去的15年里，研究者的实验室已培养了35名高级本科生，其中三分之二以上获得了科学、数学或工程学的研究生学位。