SYNTHETIC INORGANIC AND MATERIALS CHEMISTRY

无机合成与材料化学

• 批准号: 8168791
• 负责人: WILLIAM E BUHRO
• 金额: $ 0.14万
• 依托单位: WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-03-10 至 2010-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8168791
• 关键词: Behavior; Caliber; Chemistry; Collaborations; Computer Retrieval of Information on Scientific Projects Database; Dependence; Dimensions; Electronics; Electrons; Exciton; Exhibits; Funding; Grant; Institution; Nature; Optics; Performance; Property; Quantum Mechanics; Radial; Research; Research Personnel; Resources; Semiconductors; Shapes; Solutions; Source; United States National Institutes of Health; Work; catalyst; indium phosphide; nanocrystal; nanoparticle; quantum; retinal rods

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Semiconductor Quantum Wires and the Influence of Geometric Dimensionality on Quantum Confinement: Quantum-confinement effects are the dramatic changes in electronic and optical properties occurring in small semiconductor crystallites as a result of the geometric confinement of electrons and holes. When an electron-hole pair in an excited nanocrystal is squeezed into a dimension approaching the bulk exciton Bohr radius (~2-60 nm), the effective band gap of the semiconductor increases with decreas innanocrystal size. Thus, the magnitude of quantum confinement depends upon nanocrystal size and composition. But how about the nanocrystal shape? One may reasonably wonder which nanocrystal shape- the quantum well (layer), quantum wire, quantum rod (short wire), orquantum dot - should exhibit the inherently stronger quantum-confinement effects.The answer is known theoretically: 3D confinement is stronger than 2D confinement, which in turn is stronger than 1D confinement. Thus, the magnitude of quantum confinement should increase in the order wells < wires < rods < dots. My group is now providing quantitative experimental ver-ification of these predictions. We grow soluble, diameter-controlled quantum wires by solution chemistry using monodisperse metallic-nanoparticle catalysts. Spectroscopic characterization of the wires, from which their band gaps and other optical properties are determined, is conducted in collaboration with Prof. Loomis. The size dependences of the quantum-wire band gaps and other properties are compared to those of the corresponding dots, rods, and wells, and to the results of high-level theoretical calculations provided by the group of Dr. Lin-Wang Wang (Lawrence Berkeley National Lab.). Our work affirms that bodybuilders, distance runners, architects, and quantum mechanics all agree: in function, performance, and behavior - shape matters. H. Yu, J. Li, R.A. Loomis, L.-W. Wang, and W.E. Buhro,* "Two- versus three-dimensional quantum confinement in indium phosphide wires and dots," Nature Mater., 2, 517 (2003).

该子项目是利用该技术的众多研究子项目之一 资源由 NIH/NCRR 资助的中心拨款提供。子项目和 研究者 (PI) 可能已从 NIH 的另一个来源获得主要资金， 因此可以在其他 CRISP 条目中表示。列出的机构是 对于中心来说，它不一定是研究者的机构。 半导体量子线和几何维度对量子限制的影响：量子限制效应是由于电子和空穴的几何限制而在小型半导体微晶中发生的电子和光学特性的巨大变化。当受激纳米晶体中的电子-空穴对被挤压到接近体激子玻尔半径（~2-60 nm）的尺寸时，半导体的有效带隙随着纳米晶体尺寸的减小而增加。因此，量子限制的大小取决于纳米晶体的尺寸和成分。但纳米晶体的形状又如何呢？人们可能会合理地想知道哪种纳米晶体形状——量子阱（层）、量子线、量子棒（短线）或量子点——应该表现出本质上更强的量子限制效应。理论上答案是已知的：3D 限制比 2D 限制更强，而 2D 限制又强于 1D 限制。因此，量子限制的大小应按井<线<棒<点的顺序增加。我的小组现在正在对这些预测进行定量实验验证。我们使用单分散金属纳米颗粒催化剂通过溶液化学生长可溶、直径受控的量子线。与卢米斯教授合作，对金属线进行了光谱表征，从而确定了它们的带隙和其他光学特性。将量子线带隙和其他特性的尺寸依赖性与相应的点、棒和阱的尺寸依赖性以及由王林旺博士（劳伦斯伯克利国家实验室）小组提供的高级理论计算结果进行比较。我们的工作证实健美运动员、长跑运动员、建筑师和量子力学都同意：在功能、性能和行为方面——形状很重要。 H. Yu、J. Li、R.A.卢米斯，L.-W.王和 W.E. Buhro，*“磷化铟线和点中的二维与三维量子限制”，Nature Mater., 2, 517 (2003)。