MRI: Development of an Optical Hall Effect Instrumentation for non-contact Nanostructure Electrical Characterization

0922937 schubertu。技术摘要：测量复杂纳米结构材料和异质结构中的自由载流子性质对于理解这些材料中的基本和新的物理现象变得越来越不可或缺。传统的霍尔效应仪器探测自由载流子特性的能力有限，特别是在非接触式、非侵入式、非破坏性的工作模式下，但能够在空间上分辨载流子行为。该项目旨在开发一种低操作成本、可行、易于使用、桌面式、世界独一无二的光学霍尔效应仪器，用于0.1至50太赫兹（THz）光谱区域，用于研究高达8 T磁场、4 K至300 K温度范围内的样品。这项新技术测量了由于电荷位置在外部磁场中的位移而导致的长波长的横向和纵向光学双折射，作为波长、磁场方向和强度的函数。光学霍尔效应仪器使我们能够理解电荷和自旋输运性质，并将极大地促进我们对多铁隧道结构、磁电异质结构、铁磁和铁电聚合物结构、磁性和压电混合纳米结构以及新型太阳能电池材料和器件的理解。该仪器将由内布拉斯加大学林肯分校（UNL）开发，并将用于不同大学、国家实验室和研究纳米结构材料和器件电性能的公司之间的合作。该提案将整合研究生和本科生的教育与基础研究和新仪器开发，并将利用NSF-MRSEC QSPIN， 2 NSF-CAREER和NSF-DMR项目活动以及内布拉斯加大学林肯分校的跨部门和跨学院合作。MRI的开发将促进UNL与位于内布拉斯加州林肯市的J. A. woolam Co., Inc.（世界领先的光谱椭偏仪器制造商）之间在仪器开发方面的富有成效的合作伙伴关系。摘要：在纳米结构材料中，由于纳米结构的几何形状和组成的限制，电子及其带正电的对偶体空穴的运动受到新现象的控制。了解这种纳米结构中的电荷特性，将使设计新材料和设备的能力远远超过当前的技术。利用频率比当前台式计算机时钟速度快一万倍的偏振太赫兹和远红外光监测强磁场中的电子和空穴运动，揭示它们的位置和性质，并可以在这些材料中探索基本和新的物理现象。传统的方法需要电触点，这很难或根本不可能连接到纳米结构上。这种世界上独一无二的新型光学霍尔效应仪器采用穿透纳米结构的频率，在没有电接触的情况下屏蔽它们的电子和空穴特性。例如，研究用于太阳能和能量恢复的新型多功能纳米结构有望带来许多创新。该仪器将由内布拉斯加大学林肯分校（UNL）开发，并将用于不同大学、国家实验室和研究纳米结构材料和器件电性能的公司之间的合作。该提案将把研究生和本科生的教育与基础研究和新仪器开发结合起来，并促进UNL与位于内布拉斯加州林肯市的J. A. Woollam公司（世界领先的光谱椭偏仪器制造商）之间的富有成效的合作伙伴关系。

0922937SchubertU. of Nebraska-LincolnTechnical Summary: Measurement of free charge carrier properties in complex nanostructure materials and heterostructures is becoming increasingly indispensible for understanding of fundamental and new physical phenomena in such materials. Traditional electrical Hall effect instruments are limited in their ability to probe the free charge carrier properties, particularly in operation modes which are contactless, non-invasive, non-destructive and yet capable of spatially resolving the charge carrier behavior. This project aims to develop a low-operation-cost, feasible, easy-to-use, desk-top-style, and world-unique Optical Hall effect instrumentation for the 0.1 to 50 Terahertz (THz) spectral region for studying samples within magnetic fields up to 8 T, and in the temperature range between 4 K and 300 K. The new development measures the transverse and longitudinal optical birefringence at long wavelengths due to displacements of charge location in an external magnetic field, as a function of wavelength, magnetic field direction, and strength. The Optical Hall effect instrument allows understanding of charge and spin transport properties, and will greatly advance our understanding of multiferroic tunnel structures, magnetoelectric heterostructures, ferromagnetic, and ferroelectric polymer structures, magnetic, and piezoelectric hybrid nanostructures and novel solar cell materials and devices, for example. The instrumentation will be developed at the University of Nebraska-Lincoln (UNL), and will be used in collaboration between different Universities, National Laboratories and Companies working with electrical properties of nanostructure materials and devices. The proposal will integrate the education of graduate and undergraduate students with basic research and new instrumentation development, and will leverage with NSF-MRSEC QSPIN, 2 NSF-CAREER, and NSF-DMR program activities and inter-departmental and inter-collegiate collaborations within the University of Nebraska-Lincoln. The MRI development will promote productive partnerships for instrument development between UNL, and the J. A. Woollam Co., Inc. of Lincoln, Nebraska, the world-leading manufacturer of spectroscopic ellipsometry instrumentation.Layman Summary: The motion of electrons and their positively charged counterparts - holes - in nanostructure materials is governed by new phenomena due to the confinement imposed by the nanostructure geometry and composition. Knowledge of the charge properties within such nanostructures will enable design of new materials and devices with capabilities far beyond current technology. Monitoring electron and hole motions within strong magnetic fields using polarized Terahertz and Far infrared light at frequencies up to ten thousand times faster than current desktop computer clock speed reveals their location and properties, and fundamental and new physical phenomena can be explored in such materials. Traditional methods require electrical contacts, which are difficult or simply impossible to attach to the nanostructures. The new and world-unique Optical Hall effect instrumentation employs frequencies which penetrate the nanostructures and screen their electron and hole properties without electrical contacts. Many innovations are expected from studying new multifunctional nanostructures for solar and energy restoring applications, for example. The instrumentation will be developed at the University of Nebraska-Lincoln (UNL), and will be used in collaboration between different Universities, National Laboratories and Companies working with electrical properties of nanostructure materials and devices. The proposal will integrate the education of graduate and undergraduate students with basic research and new instrumentation development, and promote productive partnerships between UNL, and the J. A. Woollam Co., Inc. of Lincoln, Nebraska, the world-leading manufacturer of spectroscopic ellipsometry instrumentation.