U.S.-Pakistan Cooperative Research: Growth and Characterization of Semiconductor and Magnetic Nanocrystals Using Buffer-Layer-Assisted Growth

0353419韦弗这个项目支持约翰·H·博士和约翰·H·博士之间的合作研究项目。Weaver，伊利诺伊大学厄巴纳分校材料科学与工程系，以及巴基斯坦伊斯兰堡信息技术研究所的Irshad Bhatti博士。 他们将研究使用缓冲层辅助生长（BLAG）的半导体和磁性纳米晶体的生长和表征。 最近开发的技术具有巨大的潜力，为新的量子结构的合成。 它消除了生长中的颗粒和衬底之间的相互作用，因为衬底被稀有气体固体多层缓冲。 因此，纳米颗粒生长发生在稀有气体表面上，并且BLAG使得可以生长三维晶体和纳米尺寸的簇。在这个项目中，BLAG将用于生长磁性和半导体纳米结构，其中尺寸分布可以变化，并且可以确定其结构，磁性和光学特性。 全世界的研究人员都在试图合成纳米粒子;而计划中的方法是独一无二的，因为它允许生长几乎任何元素的纳米粒子和广泛的二元体系。在受控条件下真空生长。电子状态表征包括扫描隧道显微镜，以便可以逐个询问粒子。PI将研究尺寸分布对物理性质的影响，簇成核，生长和聚结的机制，以及簇与衬底接触时的相互作用。一个具体的目标是阐明纳米粒子的晶体结构作为磁性粒子（钴，铁）和半导体粒子（锗，硅）的大小的函数。这个项目的一个关键组成部分涉及美国和巴基斯坦的教育和培训研究生和本科生。两个团体之间的交流是可能的，来自两国的学生能够在另一个国家体验科学。联合项目将导致联合出版物和提供会议文件。有重点的讲习班、研讨会、短期课程和对更多机构的访问将丰富更广泛的社区。 该方案的一个更广泛的影响涉及在巴基斯坦伊斯兰堡的COMSATS信息技术研究所（CIIT）建立一个研究实验室。这将使巴基斯坦合作者能够在伊斯兰堡建立一个研究实验室，其中包括BLAG生长和所产生的纳米结构的光学表征。 巴基斯坦的年轻科学家将亲身体验与纳米科学和技术相关的国际兴奋。 韦弗博士和他的学生将通过建议和访问帮助建立实验室。巴基斯坦政府科学技术部（MOST）将支持CIIT的研究活动。

0353419 WeaverThis project supports a cooperative research project between Dr. John H. Weaver, Department of Materials Science and Engineering at the University of Illinois, Urbana, Illinois and Dr. Irshad Bhatti, Institute of Information Technology, Islamabad, Pakistan. They will study the growth and characterization of semiconductor and magnetic nanocrystals using buffer-layer-assisted growth (BLAG). The recently developed technique has tremendous potential for the synthesis of novel quantum structures. It eliminates the interaction between growing particles and the substrate because the substrate is buffered by a rare gas solid multilayer. Thus, nanoparticle growth occurs on the rare gas surface, and BLAG makes it possible to grow three-dimensional crystals and clusters of nanometer dimensions. In this project, BLAG would be used to grow magnetic and semiconducting nanostructures where the size distributions could be varied and their structural, magnetic, and optical properties could be determined. Researchers worldwide are trying to synthesize nanoparticles; and the planned approach is unique because it allows growing nanoparticles of almost any element and a wide range of binary systems. Growth is done in vacuo under controlled conditions. Electronic state characterization includes scanning tunneling microscopy so that the particles can be interrogated, one by one. The PIs will study the effect of size distributions on the physical properties, the mechanisms of cluster nucleation, growth, and coalescence, and the interactions of the clusters when they come into contact with the substrate. A specific goal is to elucidate the crystal structure of the nanoparticles as a function of size for magnetic particles (Co, Fe) and semiconducting particles (Ge, Si).A key component of this project involves the education and training of U.S. and Pakistani graduate and undergraduate students. Exchanges would be possible between the two groups, with students from both nations able to experience science in another country. Joint projects would lead to joint publications and contributed conference papers. Focused workshops, seminars, short courses, and visits to a larger set of institutions would enrich a broader community. A broader impact of this program involves the development of a research laboratory at the COMSATS Institute of Information Technology (CIIT), Islamabad, Pakistan. This would enable the Pakistani collaborator to set up a research laboratory in Islamabad that would include BLAG growth and optical characterization of the nanostructures produced. The young scientists in Pakistan would experience first-hand the international excitement associated with nanoscience and technology. Dr. Weaver and his students would help to establish the laboratory through advice and visits. The Ministry of Science and Technology (MOST), Government of Pakistan, will support the research activities at CIIT.