RUI: Intercalation of Heavy Metal Iodides

小行星9312916科尔曼 本论文主要研究一种新型宽禁带半导体插层化合物的形成、表征、光学性质和理论模型。 这涉及到新的层状结构重金属碘化物的宿主系统。 初步的数据表明，独特的大的意想不到的位移的光学带边和缺乏的电荷转移后，插层碘化铅和碘化铋与肼和甲基肼。 插入材料的带边以上的光吸收的大幅增加和带边以下的吸收的减少产生尖锐的光学带边，这将在调制光谱光学开关器件中具有潜在的用途。 由于这种新的插层系统似乎不遵循通常的刚性带模型，所提出的工作打算区分可能的键合模型的过程，其中包括极化，氢键，电荷转移，和供体/受体键合。 确定键合机制中的控制因素将允许优化和定制该系统的独特光学性质。 具体而言，将改变插层以测试极化率、供体强度、氢键数目和插层尺寸的影响。 将改变电导率以测试离子性和结构依赖性。 测试的物理参数将是光学透射和反射，以确定电子能带结构的可能变化;调制光谱，以确定能带结构临界点和光学开关效率;重量增加，以找到每个公式单元的嵌入量; X射线分析晶格结构的变化;磁共振嵌入迁移率和振动光谱的声子贡献。 这些目标适合于本科院校的研究。 ***

9312916 Coleman This research is concerned with the study of formation, characterization, optical properties and theoretical models of a new wide-gap semiconductor intercalation compound. This involves new host systems of layer structure heavy metal iodides. Preliminary data indicate unique large unexpected shifts of the optical band edges and the lack of charge transfer upon intercalation of lead iodide and bismuth iodide with hydrazine and methylhydrazines. A large increase in optical absorption above the band edge and a decrease in absorption below the band edge for the intercalated material produce sharp optical band edges which would have potential uses in modulation spectroscopic optical switching devices. Because this new intercalation system does not appear to follow the usual rigid band model, the proposed work intends to distinguish among the possible bonding models for the process which include polarization, hydrogen bonding, charge transfer, and donor/acceptor bonding. Determining the controlling factors in the bonding mechanism will allow optimization and tailoring of this system's unique optical properties. Specifically, intercalates will be varied to test for effects of polarizability, donor strength, number of hydrogen bonds, and intercalate size. Hosts will be varied to test for ionicity and structure dependence. Physical parameters tested will be the optical transmission and reflection to determine possible changes in the electronic band structure; modulation spectroscopy to determine band structure critical points and optical switching efficiency; weight gain to find the amount of intercalate per formula unit; x-ray analysis for lattice structure changes; magnetic resonance for intercalate mobility and vibrational spectra for phonon contributions. These goals are appropriate for research at an undergraduate institution. ***