Career Development Plan

该提案涉及两个独立的项目，它们是纳米尺度材料化学一般研究的一部分。第一个项目涉及纳米级分子晶体管（NMTs）的构建，以确定单个分子和分子聚集体的电导率机制。这些分子器件将类似于最近开发的基于量子点的单电子晶体管。为了制造这些器件，原子力显微镜纳米制造的新方法将被利用，以及传统的电子束书写技术。分子可以通过气相沉积或分子自组装放置在紧密间隔的源极和漏极之间。目的是首次在有机材料中观察库仑封锁，实现室温操作，并展示传输光谱，其中分子中可用于电荷传输的能级被揭示。这些研究的完成将导致有机材料电导率机制的重要新知识，并将定义分子电子学的重要前瞻性器件技术。第二个项目将使用一种新的扫描探针技术——近场扫描光学显微镜（NSOM），以高（50纳米）空间分辨率探测电化学界面和纳米结构的光学性质。特别是，目的是表明NSOM可以通过成像某些电化学反应的发光来绘制电化学界面的电流密度。本文将对多孔硅的发光进行研究，以验证发光是由硅纳米结构产生的，并跟踪这些纳米结构在多孔氧化物生长过程中的发展。最后，实验描述了使用NSOM作为纳米光刻工具，并作为直接测量分子间力的方法，同时测量尖端样品接触面积。通过构建和研究纳米结构，为获得新知识和开发新技术提供了巨大的机会。分子自组装技术的最新发展，特别是扫描探针显微镜，使人们能够在纳米尺度上对材料进行前所未有的操作和研究。本研究旨在利用这些新方法来探测材料和界面的纳米级性质。在第一个项目中，构建纳米级分子晶体管来确定单个分子和分子聚集体的电导率机制。这些分子器件将类似于最近开发的单电子晶体管，为分子电子学提供了一个重要的有前途的器件技术。在第二个项目中，一种新的扫描探针技术将以高（~50 nm）空间分辨率探测有机材料和电化学界面的光学性质。

Abstract 9624154 Frisbie This proposal addresses two separate projects which are part of general investigations of nanoscale materials chemistry. The first project, is concerned with the construction of nanoscale molecular transistors (NMTs) to determine electrical conductivity mechanisms in individual molecules and molecular aggregates. These molecular devices will operate analogously to recently developed single electron transistors based on quantum dots. To make these devices, new methods for nanofabrication with the atomic force microscope will be utilized as well as conventional electron beam writing techniques. Molecules can be placed between closely-spaced source and drain electrodes by vapor deposition, or by molecular self-assembly. The aim is to observe the Coulomb Blockade for the first time in organic materials, to achieve room temperature operation, and to demonstrate transport spectroscopy in which the energy levels available for charge transport in the molecules are revealed. Completion of these studies will result in significantly new knowledge of conductivity mechanisms in organic materials and will define an important prospective device technology for molecular electronics. For the second project, a new scanning probe technique, near-field scanning optical microscopy (NSOM), will be used to probe the optical properties of electrochemical interfaces and nanostructures with high (50 nm) spatial resolution. In particular, the aim is to show that NSOM can be used to map current density at electrochemical interfaces by imaging luminescence from certain electrochemical reactions. Investigation of luminescence from porous silicon will be conducted to verify that the light emission occurs from silicon nanostructures and to track the development of these nanostructures during growth of the porous oxide. Finally, experiments are described to use NSOM as a nanolithography tool and as a means for direct measurement of intermolecular forces with simultaneo us tip-sample contact area measurement. %%% Tremendous opportunities are arising for gaining new knowledge and developing new technology by building and studying nanoscale structures. Recent developments in molecular self-assembly technology and scanning probe microscopies in particular enable unprecedented manipulation and investigation of materials on the nanoscopic scale. This research is aimed at utilizing these new methods for probing nanoscale properties of materials and interfaces. In the first project, nanoscale molecular transistors are constructed to determine electrical conductivity mechanisms in individual molecules and molecular aggregates. These molecular devices will operate analogously to recently developed single electron transistors and offer an important prospective device technology for molecular electronics. In the second project, a new scanning probe technique is to probe the optical properties of organic materials and electrochemical interfaces with high (~50 nm) spatial resolution.