Electronic, Optical, and Vibrational Properties of IV - VI Semiconductor Nanocrystals

摘要：提出研究具有强电子、空穴和激子量子约束的半导体纳米晶体的性质。半导体硫族铅的纳米晶体提供了进入强约束体系的独特途径。利用拉曼光谱和远红外光谱以及连续波、纳秒和飞秒光学技术研究这些纳米晶体的电子结构、振动特性以及电子和振动态的耦合。这项研究将提供有关在强载流子约束条件下库仑相互作用重要性的详细信息。非技术文摘：将电子限制在原子大小量级的固体结构具有与相应的块状晶体截然不同的性质。该项目的目标是确定由铅盐（如硫化铅）制成的纳米结构的电子和光学特性，其中的限制效应应该比大多数其他材料更大。预计铅盐的独特特性将导致其非线性光学性质比先前研究的纳米结构强约1000倍。这种强光学非线性材料的潜在应用是光信息处理。＊＊＊

9321259 Wise Technical abstract: It is proposed to investigate the properties of semiconductor nanocrystals which exhibit strong quantum confinement of electrons, holes and excitons. Nanocrystals of the semiconducting lead chalcogenides provide unique access to the strong-confinement regime. The electronic structure, the vibrational properties, and the coupling of the electronic and vibrational states of these nanocrystals will be investigated with Raman and far-infrared spectroscopies as well as continuous wave, nanosecond and femtosecond optical techniques. This research will provide detailed information about the importance of Coulomb interactions under conditions of strong confinement of charge carriers. Non-technical abstract: Solid structures which confine electrons to dimensions on the order of atomic sized dimensions have properties which differ drastically from those of the corresponding bulk crystals. The goal of this project is to determine the electronic and optical properties of nanostructures made of the lead salts (such as lead sulfide), where the effects of confinement should be greater than in most other materials. The unique features of the lead salts are expected to lead to nonlinear optical properties approximately 1000 times stronger than those of previously investigated nanostructures. The potential applications of such strongly optically nonlinear materials is in optical information processing. ***