Raman, Brillouin, Infrared and Modulation Spectroscopy of Collective and Localized Excitations in Tetrahedrally Coordinated Semiconductors

普渡大学物理系教授A.K.Ramdas和S.Rodriguez的这项研究集中于研究一系列四面体配位半导体表现出的新光谱现象，这些半导体在原子结构、晶格动力学和电子能带结构方面具有共同特征。将开展一项丰富的研究计划，包括利用傅里叶变换红外(FTIR)、拉曼和光致发光光谱研究同位素控制的钻石、碳化硅多型体和II-VI化合物半导体中施主束缚电子和受主束缚空穴的电子态的性质。此外，还将利用压电谱和磁谱学来推断杂质的位置对称性，以及它的束缚态的简并、形变势能常数和g因子特征。此外，还将用FTIR研究II-VIS、I-III-VI2和II-IV-V2黄铜矿中等电子杂质和补偿杂质的局域振动和能隙模式，以及II-VI和黄铜矿基稀磁半导体中磁激发所揭示的sp-d和d-d交换作用。这些现象和系统构成了一个广泛的研究计划，其对当代固体物理和材料科学各个领域的贡献将有助于我们理解新材料的基本行为，并有助于将它们纳入各种技术设备。普渡大学物理系A.K.Ramdas教授和S.Rodriguez教授的这项研究集中于研究一系列四面体配位半导体表现出的新光谱现象，这些半导体在原子结构、晶格动力学和电子能带结构方面具有共同特征。将开展一项丰富的研究计划，包括利用傅里叶变换红外(FTIR)、拉曼和光致发光光谱研究同位素控制的钻石、碳化硅多型体和II-VI化合物半导体中施主束缚电子和受主束缚空穴的电子态的性质。此外，还将利用压电谱和磁谱学来推断杂质的位置对称性，以及它的束缚态的简并、形变势能常数和g因子特征。此外，还将用FTIR研究II-VIS、I-III-VI2和II-IV-V2黄铜矿中等电子杂质和补偿杂质的局域振动和能隙模式，以及II-VI和黄铜矿基稀磁半导体中磁激发所揭示的sp-d和d-d交换作用。这些现象和系统构成了一个广泛的研究计划，其对当代固体物理和材料科学各个领域的贡献将有助于我们理解新材料的基本行为，并有助于将它们纳入各种技术设备。这项研究是与研究生和博士后研究助理共同进行的。这一合作旨在培养下一代科学家和工程师*

9800858Ramdas This research by Professors A.K. Ramdas and S. Rodriguez of the Department of Physics of Purdue University is focused on the investigation of novel spectroscopic phenomena exhibited by a range of tetrahedrally coordinated semiconductors which share common features in their atomic architecture, lattice dynamics, and electronic band structures. A rich program of investigations will be pursued, including the study of the nature of the electronic states of donor-bound electrons and acceptor-bound holes in isotopically controlled diamonds, in silicon carbide polytypes, and in II-VI compound semiconductors by Fourier transform infrared (FTIR), Raman, and photoluminescence spectroscopy. Also piezo- and magneto-spectroscopy will be used to deduce the site symmetry of the impurity, and the degeneracies, deformation potential constants, and g-factors characteristic of its bound states. Further, localized vibrational and gap modes of isoelectronic and compensated impurities in II-VIs, I-III-VI2, and II-IV-V2 chalcopyrites will be studied by FTIR as are the sp-d and d-d exchange interactions as revealed in the magnetic excitations in the II-VI and chalcopyrite based diluted magnetic semiconductors. These and other phenomena and systems constitute a wide ranging research program whose contributions to various areas of contemporary solid state physics and materials science will aid in our understanding of the fundamental behavior of novel materials and assist in their incorporation in varied technological devices. %%% This research by Professors A.K. Ramdas and S. Rodriguez of the Department of Physics of Purdue University is focused on the investigation of novel spectroscopic phenomena exhibited by a range of tetrahedrally coordinated semiconductors which share common features in their atom ic architecture, lattice dynamics, and electronic band structures. A rich program of investigations will be pursued, including the study of the nature of the electronic states of donor-bound electrons and acceptor-bound holes in isotopically controlled diamonds, in silicon carbide polytypes, and in II-VI compound semiconductors by Fourier transform infrared (FTIR), Raman, and photoluminescence spectroscopy. Also piezo- and magneto-spectroscopy will be used to deduce the site symmetry of the impurity, and the degeneracies, deformation potential constants, and g-factors characteristic of its bound states. Further, localized vibrational and gap modes of isoelectronic and compensated impurities in II-VIs, I-III-VI2, and II-IV-V2 chalcopyrites will be studied by FTIR as are the sp-d and d-d exchange interactions as revealed in the magnetic excitations in the II-VI and chalcopyrite based diluted magnetic semiconductors. These and other phenomena and systems constitute a wide ranging research program whose contributions to various areas of contemporary solid state physics and materials science will aid in our understanding of the fundamental behavior of novel materials and assist in their incorporation in varied technological devices. The research is conducted jointly with graduate students and post doctoral research associates. This collaboration serves to train the next generation of scientists and engineers ***