NER: Spin-Polarized Injection and Transport in Polymers

这项纳米探索性研究(NER)计划是应“纳米科学与工程”(NSF 02-148)的征集而提交的。该项目对有机和聚合物导体中的自旋注入和输运进行了探索性研究。该方法是利用固态磁电极作为自旋极化载流子的来源来制备有机异质结构，并利用分子自组装和相关技术来操纵纳米尺度的界面性质。自旋将被注入半导体和导电聚合物/有机薄膜。几个符合“探索性”时间尺度和支持水平的具体系统将被讨论，包括巨磁电阻的有机模拟，自旋注入有机/聚合物发光二极管，以及磁性纳米晶体通过有机层的隧道效应。在这些系统中，界面被认为是至关重要的，因为在电子电荷的情况下，它通过电子势垒高度来控制注入特性，在磁极的情况下，它通过自旋散射特性来控制注入特性。预计界面控制将由有机体系提供，通过使用界面自组装单分子层来操纵自旋注入性能，并通过化学或电化学手段对阻挡聚合物进行表面掺杂。该项目解决了材料科学中具有高度技术相关性的主题领域的基本探索性研究问题；它被认为是一项高风险/高回报的活动。导电聚合物和分子有机物正迅速成为重要的技术材料，因为它们独特地融合了半导体的电子性质和有机/聚合物材料的灵活性。已经用有机材料展示了各种各样的电子器件，如发光二极管、激光二极管和场效应管。由此产生的“塑料”电子器件的优点包括易于制造、可伸缩性，以及对界面形态和电子特性的分子级别控制。该项目围绕纳米结构、新现象和量子控制的研究和教育主题。该计划的一个重要特点是通过在一个具有根本意义和技术意义的领域对学生进行培训，将研究和教育结合起来。该项目预计将产生广泛的影响，提供独特的教育机会和基础知识，对潜在开发具有有机电子学和固态自旋电子学优点的有机自旋电子器件至关重要。该项目由MPS/DMR/EM和MPS/DMR/POL计划共同支持。*

This Nanoscale Exploratory Research (NER) proposal was submitted in response to the solicitation "Nanoscale Science and Engineering" (NSF 02-148). The project undertakes an exploratory study of spin injection and transport in organic and polymeric conductors. The approach is to fabricate organic heterostructures, employing solid-state magnetic electrodes as a source of spin polarized carriers, and manipulate the nanoscale interfacial properties using molecular self-assembly and related techniques. Spin will be injected into semiconducting and conducting polymer/organic thin films. Several specific systems consistent with "exploratory" time scales and support levels, including the organic analog of giant magnetoresistance, spin-injected organic/polymer light-emitting diodes, and tunneling from magnetic nanocrystals through organic layers will be addressed. In these systems, the interface is judged to be of critical importance since it controls injection characteristics through the electronic barrier height in the case of electronic charge, and spin-scattering characteristics in terms of magnetic electrodes. It is anticipated that interfacial control will be afforded by organic systems to manipulate spin-injection properties through the use of interfacial self-assembled monolayers, and surface doping of the barrier polymer by chemical or electrochemical means. %%% The project addresses basic exploratory research issues in a topical area of materials science with high technological relevance; it is considered a high risk/high pay-off activity. Conducting polymers and molecular organics are rapidly becoming technologically important materials because of their unique fusion of semiconducting electronic properties with the flexibility of organic/polymeric materials. A wide variety of electronic devices have been demonstrated with organic materials, such as light-emitting diodes, laser diodes, and field-effect transistors. The advantages of resulting 'plastic' electronic devices include ease of fabrication, scalability, and molecular-level control of interfacial morphology and electronic characteristics. The project encompasses the research and education theme of Nanoscale Structures, Novel Phenomena, and Quantum Control. An important feature of the program is the integration of research and education through the training of students in a fundamentally and technologically significant area. The project is expected to have broad impact by providing unique educational opportunities and basic knowledge critical to potential development of organic spintronic devices having advantages of both organic electronics and solid-state spintronics. The project is jointly supported by the MPS/DMR/EM and MPS/DMR/POL programs.***