Charge Tunneling in Organic Matter

有机物中的电荷隧道

• 批准号: 1506993
• 负责人: George Whitesides
• 金额: $ 57.88万
• 依托单位: Harvard University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-07-15 至 2018-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1506993&HistoricalAwards=false
• 关键词: Charge; Tunneling; Organic; Matter

With this award, the Macromolecular, Supramolecular and Nanochemistry (MSN) Program of the Division of Chemistry is funding Professor George Whitesides of Harvard University to investigate methods to control the flow of electrical currents through thin layers of materials that are normally electrically insulating. When these materials are sufficiently thin (1-2 nanometers, or less than 20 atoms in thickness), they allow electrical charge to cross by a fundamentally different process called tunneling. In tunneling, the charge, faced with a normally insulating barrier, simply passes through it. In understanding tunneling of charge through normally insulating organic matter, this project pursues three objectives: the design of new materials that either enhance or decrease tunneling; the introduction of students on this project to a style of science that requires integration of skills from organic synthesis and materials science to quantum physics, and strengthening the U.S. technical workforce; the design, construction, and demonstration of new tools for studying tunneling that are broadly useful, and sufficiently simple for use at the undergraduate college level in science teaching. The objective of this project is to understand charge tunneling through thin, insulating organic films. It will use a junction developed specifically for this purpose that has three parts: i) an electrode of flat gold or silver; ii) a self-assembled monolayer (SAM) of an organic or organometallic compound (or mixture of compounds as the tunneling barrier; iii) a second electrode comprising a compliant structure composed of a drop of liquid eutectic gallium-indium alloy, covered with a thin, conducting film of gallium oxide. The project will measure the tunneling current across this junction at low voltages (V ~ 0.5V), using a number of SAMs designed to test theories relating to rates of tunneling, to the molecular and electronic structure of the molecules across which tunneling is occurring. The project will have two objectives: i) to validate a level of theory adequate to explain tunneling rates; ii) to use this theory to predict new types of tunneling mechanisms, and new phenomena involving tunneling, through organic matter. The desired outcome of the work is a fundamental understanding of the orbital structures particularly the highest energy occupied molecular orbitals, or HOMOs and the electronic couplings between them, that lead to either particularly high or particularly low charge tunneling rates. Both outcomes would be interesting, and both, ultimately, may be useful in the design of molecular electronic and organic electronic devices.

有了这个奖项，化学系的大分子，超分子和纳米化学（MSN）计划正在资助哈佛大学的乔治怀特塞德斯教授研究控制电流流过通常是电绝缘的薄层材料的方法。当这些材料足够薄（1-2纳米，或厚度小于20个原子）时，它们允许电荷通过一个根本不同的过程（称为隧穿）穿过。在隧穿过程中，电荷面对正常绝缘的势垒，只是简单地穿过它。在理解电荷穿过正常绝缘的有机物质的隧穿过程中，本项目追求三个目标：设计新材料，增强或减少隧穿;向该项目的学生介绍一种科学风格，需要从有机合成和材料科学到量子物理学的综合技能，和加强美国的技术劳动力;设计，建造和演示用于研究隧道的新工具，这些工具广泛有用，并且足够简单，可用于本科大学的科学教学。 这个项目的目的是了解通过薄的绝缘有机膜的电荷隧穿。它将使用专门为此目的开发的结，其具有三个部分：i）平坦的金或银电极; ii）有机或有机金属化合物（或化合物的混合物）的自组装单层（SAM）作为隧穿势垒; iii）第二电极，其包括由液体共晶镓-铟合金滴组成的顺应性结构，覆盖有氧化镓的导电薄膜。 该项目将测量在低电压（V ~ 0.5V）下穿过该结的隧穿电流，使用许多SAM来测试与隧穿速率相关的理论，以及隧穿发生的分子的分子和电子结构。 该项目将有两个目标：i）验证足以解释隧穿率的理论水平; ii）使用该理论预测新型隧穿机制，以及涉及隧穿的新现象，通过有机物。 这项工作的预期成果是对轨道结构的基本理解，特别是最高能量占据的分子轨道，或HOMO以及它们之间的电子耦合，导致特别高或特别低的电荷隧穿率。这两个结果都很有趣，最终都可能在分子电子和有机电子器件的设计中有用。