Presidential Young Investigator Award

总统青年研究员奖

• 批准号: 8657629
• 负责人: R. J. Dwayne Miller
• 金额: $ 31.2万
• 依托单位: University of Rochester
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1987
• 资助国家: 美国
• 起止时间: 1987-07-01 至 1993-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8657629&HistoricalAwards=false
• 关键词: Presidential; Young; Investigator; Award

The main theme of Professor Miller's research is to understand the primary processes involved in electron transport and energy transport in condensed media. Currently, his group is investigating the dynamics of interfacial electron transfer at a single crystal liquid interface and the subsequent effect of the charge transfer on the solution structure. The time resolved dynamics of this process are intimately related to the mechanism for the electron transfer step, a detailed understanding of which is important both for its fundamental nature and its application in surface chemistry. Interfacial electron transfer occurs on a picosecond timescale (10-12 sec) over spatial dimensions of only a few angstroms. In order to study this phenomenon, they are taking advantage of recent developments in picosecond laser spectroscopy and semiconductor technology. With the advent of efficient semiconductor liquid junction photovoltaics, it is now possible to optically trigger the interfacial electron transfer process with high quantum yield. Ultrasensitive techniques such as picosecond transient grating or electro-optic sampling are being used to selectively study, in-situ, the electron transfer dynamics. Studies in the future will involve the use of recently-developed quantum well semiconductor liquid junction devices that provide monoenergetic electrons to study exclusively the phenomena of outer sphere (solvent) or inner sphere (intramolecular) repolarization that accompanies electron transfer at a liquid interface. The ultimate goal is to provide a detailed study of interfacial electron transfer dynamics which will serve as a valuable testing ground for microscopic models of electron transfer. Concurrently, Professor Miller is interested in how excess energy is repartitioned during an exothermic reaction in the solution phase. This interest is intimately linked to his optical studies of interfacial electron transfer which involves dissipation of 1 eV excess energy on an extremely fast timescale. Vibrational energy relaxation pathways to the solvent lattice are very different for different molecular systems. These differences are only now beginning to be understood. New approaches to this problem involve the use of picosecond transient thermal grating formation and Antistokes Raman studies of vibrationally highly excited molecules.

米勒教授研究的主要主题是了解凝聚态介质中电子输运和能量输运的主要过程。目前，他的团队正在研究单晶液体界面上的界面电子转移动力学以及电荷转移对溶液结构的后续影响。这一过程的时间分辨动力学与电子转移步骤的机制密切相关，详细了解这一过程对其基本性质及其在表面化学中的应用都很重要。界面电子转移发生在皮秒时间尺度（10-12秒）上，空间尺寸仅为几埃。为了研究这一现象，他们正在利用皮秒激光光谱和半导体技术的最新发展。随着高效半导体液体结光伏技术的出现，现在可以用高量子产率的光触发界面电子转移过程。超灵敏技术如皮秒瞬态光栅或电光采样被用于选择性地原位研究电子传递动力学。未来的研究将涉及使用最近开发的量子阱半导体液体结装置，该装置提供单能电子，专门研究伴随电子在液体界面转移的外球（溶剂）或内球（分子内）复极化现象。最终目标是提供界面电子转移动力学的详细研究，这将作为电子转移微观模型的有价值的试验场。同时，米勒教授对在溶液阶段的放热反应中多余的能量是如何重新分配的很感兴趣。这种兴趣与他对界面电子转移的光学研究密切相关，该研究涉及在极快的时间尺度上耗散1ev多余能量。对于不同的分子体系，到达溶剂晶格的振动能量弛豫途径是非常不同的。人们现在才开始了解这些差异。解决这个问题的新方法包括使用皮秒瞬态热光栅形成和振动高激发分子的反斯托克斯拉曼研究。