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.

****非技术抽象****石墨烯是一种新型的碳材料，由一片厚的碳组成。 该材料于2004年发现，具有从透明的导电膜（用于太阳能电池）到超高速晶体管的电子应用的巨大希望。 该个体研究者奖支持一个主要的本科机构的研究项目，该项目将研究石墨烯的电导率的变化速度，这与高速石墨烯电子产品的开发有关。 预计石墨烯的电导率可能会在非常快的时间范围内改变。 为了研究电导率的快速变化，石墨烯样品将通过光的超短脉冲激发，随后将通过Terahertz辐射的超短脉冲来测量导致电导率的变化。 在一系列条件下的电导率测量将使控制石墨烯的电子特性的基本过程分离。 这项研究还将有助于培训有关光子学和实验性凝结物理学的本科科学专业的学生。 在过去的15年中，研究者的实验室培训了35名高级本科生，其中三分之二以上攻读了科学，数学或工程学的研究生学位。 该单独的研究者奖支持一个项目，该项目将使用时间分辨的THZ光谱法研究石墨烯和超薄石墨的载体动力学。 现在可以轻松地从氧化石墨烯和石墨烯溶液中产生石墨烯薄片的膜。 时间分析的THZ和红外光谱是用于研究这些薄片的电子特性的合适工具。这些测量值使用光学或红外泵脉冲激发样品并延迟THZ脉冲来探测所得的电导率瞬态变化。 预计该研究将确定由石墨的机械或化学去角质形成的石墨烯薄片中的电子和孔散射率，寿命和迁移率。 通过这种方式，测量结果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，研究人员的实验室培训了35名高级本科生，其中三分之二以上攻读了科学，数学或工程学的研究生学位。