Understanding Electronic and Spin Structure at Organic / Metal Interfaces: Surfaces and Symmetry

了解有机/金属界面的电子和自旋结构：表面和对称性

• 批准号: 1954571
• 负责人: Oliver Monti
• 金额: $ 50.05万
• 依托单位: University of Arizona
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-08-01 至 2024-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1954571&HistoricalAwards=false
• 关键词: Understanding; Electronic; Spin; Structure; Organic

As electronics technology is driven to produce greater memory and processing power in smaller devices, research increasingly focuses on molecules as the building blocks for electronics circuitry. Larger traditional circuit elements made of metal and semiconductor materials must conduct and store not only electrical charge, but also magnetic information. Electrons hold a negative charge, which allows them to conduct electricity when they move. Electrons also act like magnets because they possess a property called “spin”. If revolutionary molecule-based electronics are to become a reality, we must be able to understand and control how charge and spin flow not only through individual molecules, but between molecules and other materials (other parts of the circuit). In this project, funded by the Chemical Structure, Dynamics, and Mechanism-A (CSDM-A) program of the Chemistry Division, Professor Oliver Monti and his students at the University of Arizona are investigating how charge and spin flow at contact points with other materials. They are studying molecules on metal surfaces, as well as molecules on metal surfaces that have been modified with other molecules, to modify the contact condition. The Monti research group uses a combination of laser-based techniques and scanning tunneling microscopy (STM) which can image individual atoms and molecules. The research seeks to discover the important molecular structural factors that determine charge- and spin-flow in molecule based electronic elements. The graduate students receive training and experience in advanced chemistry, optical physics and atomic microscopy. This training is expected to prepare them well for the quantum information science revolution. In addition to the formal training of doctoral students, Professor Monti is developing a program for undergraduate student veterans at Arizona to gain research experience and personalized mentoring toward a successful career in science and engineering.The project focuses on tailoring the interfacial electronic structure and charge-transfer dynamics at organic semiconductor / metal interfaces. The research entails tailoring the surface electronic structure using epitaxial layers of Ag on Cu(111) to change the surface electron wavelength, the surface electron density, and the surface symmetry. The effects of these systematic changes on surface processes are examined using a combination of low-temperature scanning tunneling microscopy and steady-state and time-resolved photoemission spectroscopy. Processes such as molecular self-assembly, interfacial electronic structure and charge-transfer dynamics are thus characterized over a wide range of surface electronic properties without varying the chemical nature of the interface. Surface modifications are also being developed to facilitate Rashba splitting without the need for an external magnetic field. This study involves the adsorption of organic semiconductors that support large electric dipoles or can induce orbital mixing at the interface. If this type of Rashba splitting is achieved, it could have significant implications for the control and manipulation of spin states at organic/metal interfaces. The broader impacts of this research include the advancement of technologies to develop novel highly efficient electronic devices that may also harness the spin degrees of freedom, which in turn are important in quantum processing. This project is providing a vehicle for training both graduate and undergraduate students as well as mentoring and research opportunities for veterans enrolled in science and engineering degree programs at the University of Arizona.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

由于电子技术被驱动以在较小的设备中产生更大的记忆力和处理能力，因此研究越来越重视分子作为电子电路的基础。由金属和半导体材料制成的较大的传统电路元素不仅必须进行和存储电荷，还必须存储磁性信息。电子设备具有负电荷，这使他们在移动时可以进行电力。电子产品也像磁铁一样起作用，因为它们具有称为“自旋”的特性。如果基于革命性分子的电子将成为现实，我们必须能够理解和控制电荷和旋转如何通过单个分子，而且在分子和其他材料之间（电路的其他部分）之间的电荷流动。在这个项目中，由化学部门的化学结构，动力学和机制（CSDM-A）计划资助，奥利弗·蒙蒂（Oliver Monti）教授及其学生的学生正在研究如何在与其他材料的接触点上的电荷和旋转流量。他们正在研究金属表面上的分子，以及已通过其他分子修饰的金属表面上的分子，以改变接触条件。蒙蒂研究小组使用基于激光的技术和扫描隧道显微镜（STM）的组合，可以对单个原子和分子进行图像。该研究试图发现确定基于分子电子元件的电荷和自旋流的重要分子结构因子。研究生接受高级化学，光学物理和原子显微镜的培训和经验。预计这项培训将为量子信息科学革命做好准备。除了对博士生的正式培训外，蒙蒂教授还正在为亚利桑那州的本科生退伍军人开发一项计划，以获得研究经验和个性化的心理，以实现科学和工程领域的成功职业。研究实体使用Cu上的AG（111）上的AG的外延层调整表面电子结构，以改变表面电子波长，表面电子密度和表面对称性。这些系统变化对表面过程的影响，使用低温扫描隧道隧道显微镜和稳态以及时间分辨光发射光谱的组合进行了检查。因此，诸如分子自组装，界面电子结构和电荷转移动力学之类的过程在不改变界面的化学性质的情况下进行了广泛的表面电子特性的特征。还开发了表面修饰，以促进Rashba分裂而无需外部磁场。这项研究涉及支持大型电偶极子或可以在界面诱导轨道混合的有机半导体的添加吸收。如果实现了这种类型的RashBA分裂，它可能对有机/金属界面的自旋状态的控制和操纵具有重要意义。这项研究的更广泛的影响包括技术发展新型高效的电子设备的技术，这些电子设备也可能利用自由度的自由度，而自由度又在量子处理中很重要。该项目正在为培训研究生和本科生培训的工具，以及亚利桑那大学参加科学和工程学位课程的退伍军人的心理和研究机会。这项奖项反映了NSF的法定任务，并被认为是通过基金会的知识分子优点和更广泛的影响审查标准来通过评估来通过评估来支持的。