NER: Combined UHV and Liquid Phase (CULP) Processing of Self-Assembled Nanostructures and Novel Interfaces

这项纳米探索性研究(NER)计划是应“纳米科学与工程”(NSF 02-148)的征集而提交的。该项目旨在推进自组装量子点和新型界面的制造技术，并拓宽涉及纳米粒子的动力学过程的科学知识。该方法利用惰性液体作为介质来形成金属、半导体和绝缘体的簇，并随后利用干燥液体的表面张力来相对于衬底表面上的现有图案定位自组装纳米颗粒。通过在小室中对样品施加超过三点压力的压力，而不越过相图上的固-气边界，混合的固体膜有望通过调节其温度而转变为液体。预计，原子在液体中的大扩散系数将促进溶解物种在纳米尺度上自组装成具有物理尺寸的颗粒。在液相加工后，薄膜要么重新冻结到固相中，以便随后干燥，以避免表面张力效应，要么在真空中干燥，以允许液滴的线张力移动，并可能使纳米颗粒与衬底上现有的图案对齐。自组装纳米颗粒的形态和结构与工艺参数的依赖关系将通过包括AFM和TEM在内的微观技术进行研究，后者通过与朗讯技术贝尔实验室的合作进行。还将表征纳米粒子与衬底之间的界面处的传输特性。该项目解决了材料科学和工程领域的基本探索性研究问题，具有高度的技术相关性；它被认为是一项高风险/高回报的活动。该项目围绕NSE纳米结构、新现象和量子控制的研究和教育主题。该计划的一个重要特点是通过在一个重要的技术领域对学生进行培训，将研究和教育结合起来。这个项目背后的基本概念从根本上来说很简单，研究生或本科生很容易理解，然后他们可以对实验设置和程序的设计做出重大贡献。一个处理基本概念的网站被建立起来，并链接到布鲁克林学院(Brooklyn College)的一门本科物理课程，该学院的学生经常访问该课程，该学院的少数民族入学率很高。拟议的部分研究在工业实验室进行，让学生有机会接触到工业研究环境和人员，也让工业学者有机会分享他们在布鲁克林学院的经验和知识。由于实验的跨学科性质，将鼓励学生通过向其他领域的专家寻求指导和帮助来拓宽他们的理解。此外，PI还参加了校园少数族裔研究职业机会(MARC)方案，通过该方案，他目前正在指导三名少数族裔学生。对这个项目的参与者来说，接触纳米技术等竞争激烈领域的研究活动将是非常有价值的。该项目由MPS/DMR/EM和ENG/CTS/CRP-KCMP方案共同支持。*

This Nanoscale Exploratory Research (NER) proposal was submitted in response to the solicitation "Nanoscale Science and Engineering" (NSF 02-148). The project aims to advance fabrication technologies for self-assembled quantum dots and novel interfaces, and to broaden the scientific knowledge of kinetic processes involving nanoparticles. The approach utilizes an inert liquid as a medium to form clusters of metals, semiconductors, and insulators, and subsequently, the surface tension of the drying liquid for positioning self-assembled nano-particles with respect to an existing pattern on the substrate surface. By subjecting samples to pressures exceeding the triple-point pressure, in-situ in a small chamber, without crossing the solid-gas boundary on the phase diagram, the mixed solid film is expected to be converted to the liquid phase by adjusting its temperature. It is anticipated that the large diffusivity of atoms in the liquid phase will facilitate self-assembly of the dissolved species into particles with physical dimensions on the nanometer scale. After processing in the liquid phase, the thin films are either refrozen into the solid phase for subsequent drying to avoid surface tension effects, or dried in vacuum to allow the line tension of the liquid droplet to move, and possibly align the nano-particles with existing patterns on the substrate. The dependencies of the morphology and structure of self-assembled nanoparticles on the processing parameters will be studied by microscopic techniques, including AFM and TEM, the latter performed through collaboration with Lucent Technologies Bell Labs. The transport properties at the interfaces between the nano-particles and the substrate will also be characterized. %%% The project addresses basic exploratory research issues in a topical area of materials science and engineering with high technological relevance; it is considered a high risk/high pay-off activity. The project encompasses the NSE research and education theme of Nanoscale Structures, Novel Phenomena, and Quantum Control. An important feature of the program is the integration of research and education through the training of students in a technologically significant area. The basic concepts behind this project are fundamentally simple and may be readily understood by graduate, or undergraduate, students, who can then contribute significantly to the design of the experimental setup and procedures. A website dealing with the basic concepts is set-up and linked to an undergraduate physics course regularly accessed by students at Brooklyn College, which has a high minority enrollment. Parts of the proposed research are conducted at an industrial laboratory, giving students valuable exposure to an industrial research environment and personnel, and also opportunities for industrial scholars to share their experience and knowledge at Brooklyn College. Due to the interdisciplinary nature of the experiments, students will be encouraged to broaden their understanding by seeking guidance and help from experts in other areas. In addition, the PI participates in the Minority Access to Research Careers (MARC) program on campus, through which he is presently mentoring three minority students. Access/exposure to research activities in highly competitive areas such as nanotechnology will be very valuable for participants in this program. The project is jointly supported by the MPS/DMR/EM and the ENG/CTS/CRP-KCMP programs.***