NER: Investigation of Electronic Transport in Carbon Nanotubes Using an Ultrafast Photoconduction Technique

该提案是根据NSE， NSF-0019收到的。碳纳米管由于其独特的性质，特别是其作为一维导体的行为和在室温下在几微米范围内的弹道性质，而成为人们感兴趣的电子导体。该领域的研究人员正在开发纳米管中电子传导的总体图景。虽然电流的瞬态响应预计相当快（皮秒范围），但目前纳米管导电性能的实验数据主要是在低频或静态测量中获得的。为了阐明纳米管中基本的电流传输过程，提出了一项实验和理论努力，以发展表征技术，从而允许测量通过纳米管导体的瞬态电流响应。这项工作将解决两个问题：1)纳米管导体与适当的高速光导体材料的集成；2)基于高速脉冲激光系统的泵浦/探针测量的纳米级导体表征技术的发展。期望这项工作将揭示这些有趣的电子材料的传导过程，并为这些材料与其他电子材料（包括半导体器件结构）的集成提供重要的能力。

This proposal was received in response to NSE, NSF-0019. Carbon nanotubes are of interest as electronic conductors because of their unique properties, notably their behavior as 1-D conductors and their ballistic nature over several microns at room temperature. A general picture of electronic conduction in nanotubes is being developed by researchers in the field. Although the transient response of current flow is expected to be quite rapid (picosecond range), present experimental data for conduction properties of nanotubes is primarily obtained at low frequencies or in static measurements. In order to shed light on the fundamental current transport processes in nanotubes, an experimental and theoretical effort is proposed to develop characterization techniques which would allow the measurement of the transient current responses through nanotube conductors. This work will address two issues: i) the integration of nanotube conductors with appropriate high speed photoconductor materials and ii) the development of characterization techniques for nanoscale conductors based on pump/probe measurements using high speed pulsed laser systems. It is expected that the proposed work will shed light on the conduction processes of these interesting electronic materials and provide important capabilities for integration of these materials with other electronic materials, including semiconductor device structures.