Raman, Brillouin, Infrared and Modulation Spectroscopy of Collective and Localized Excitations in Crystals and their Heterostructures

晶体及其异质结构中集体和局域激发的拉曼光谱、布里渊光谱、红外光谱和调制光谱

• 批准号: 8921717
• 负责人: Anant Ramdas
• 金额: $ 23.7万
• 依托单位: Purdue Research Foundation
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1990
• 资助国家: 美国
• 起止时间: 1990-04-15 至 1993-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8921717&HistoricalAwards=false
• 关键词: Raman; Brillouin; Infrared; Modulation; Spectroscopy

This proposal focusses on theoretical and experimental investigations on tetrahedrally co-ordinated II-VI semiconductors (including diluted magnetic semiconductors: DMS's) and their heterostructures as well as II-VI/III-V and III-V heterostructures, the heterostructures being grown by molecular beam epitaxy (MBE). The investigations will address fundamental issues such as the nature of the ground and excited states of the transition metal (magnetic) ions in the tetrahedral environment of the II-VI semiconductors; the spin-spin exchange interaction between the magnetic ions and the band electrons; long range order; and electronic states of donors and acceptors. The new physics associated with MBE-grown quantum well structures will be studied in the context of the reduced dimensionality, interfaces, band off-sets and elastic strains. Raman, Brillouin, infrared and modulation spectroscopy will be exploited to discover and delineate the collective and localized excitations, with and without external perturbation (stress and magnetic). Theoretical investigations in parallel will provide motivation and framework for special lines of investigation and analysis of experimental results.

该提案重点关注四面体配位II-VI半导体（包括稀释磁性半导体：DMS）及其异质结构以及II-VI/III-V和III-V异质结构的理论和实验研究，这些异质结构是通过分子生长的束外延（MBE）。 研究将解决一些基本问题，例如II-VI半导体四面体环境中过渡金属（磁性）离子的基态和激发态的性质；磁性离子与带状电子之间的自旋-自旋交换相互作用； 长程订单；以及捐赠者和接受者的电子状态。 与 MBE 生长的量子阱结构相关的新物理将在降维、界面、能带偏移和弹性应变的背景下进行研究。 将利用拉曼光谱、布里渊光谱、红外光谱和调制光谱来发现和描述集体和局部激发，无论有或没有外部扰动（应力和磁场）。 并行的理论研究将为特殊的研究和实验结果分析提供动力和框架。