Dynamics of Local Vibrational Modes in Semiconductors

该项目的目标是阐明半导体中局部振动模式（LVMs）的动力学，并将振动能量流的速率和路径与半导体中的热和电子刺激的缺陷和杂质反应和迁移联系起来。方法是通过高分辨红外吸收光谱、瞬态漂白和光子回波实验，测量与H、B、C、O和N有关的点缺陷的振动寿命和退相时间随掺杂浓度、温度、单轴应力和同位素替代的变化。这些研究将有助于评估能量弛豫机制，并进一步了解氢与掺杂杂质的相互作用。感兴趣的材料包括掺杂的Si、Ge和GaX（X = As、N、P）。此外，问题将得到解决，关于振动弛豫和转移通道，耦合到弯曲模式，以及在振动弛豫过程中的局部结构和晶体位点的作用。该项目解决了与具有技术相关性的电子材料相关的基础研究问题。该项目的一个重要特点是高度重视教育，并将研究与教育相结合。该项目的一个主要重点将是研究生和本科生在一个跨学科领域的教育，包括现代光学，材料科学和计算建模。

The goal of this project is to elucidate the dynamics of local vibrational modes (LVMs) in semi-conductors, and to connect the rates and pathways of vibrational energy flow to thermally and electronically stimulated defect and impurity reactions and migration in semiconductors. The ap-proach is to perform high-resolution infrared absorption spectroscopy, transient bleaching and photon-echo experiments to measure the vibrational lifetime and dephasing time of point defects related to H, B, C, O, and N as a function of dopant concentration, temperature, uniaxial stress and isotope substitution. These studies will assist evaluation of energy relaxation mechanisms and further understanding of the interaction of hydrogen with dopant impurities in semiconduc-tors. Materials of interest include doped Si, Ge, and GaX (X = As, N, P). Additionally, questions will be addressed regarding vibrational relaxation and transfer channels, coupling to bending modes, and the role of local structure and crystal site in the vibrational relaxation process. %%% The project addresses fundamental research issues associated with electronic materials having technological relevance. An important feature of the project is the strong emphasis on education, and the integration of research and education. A major focus of the project will be the education of graduate and undergraduate students in an interdisciplinary field including modern optics, ma-terials science and computational modeling.***