NER: Nanoscale Molecular Spintronic Materials and Devices

NER：纳米级分子自旋电子材料和器件

• 批准号: 0204978
• 负责人: Jing Shi
• 金额: $ 8.5万
• 依托单位: University of Utah
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-08-01 至 2004-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0204978&HistoricalAwards=false
• 关键词: NER; Nanoscale; Molecular; Spintronic; Materials

This proposal was submitted in response to the Nanoscale Science and Engineering Initiative, Program Solicitation NSF 01-157, in the NER category. The proposal focuses on (a). the fabrication of planar spin-valve and light-emitting devices using ferromagnetic eletrodes and pi-conjugated materials; (b) the study of organic/inorganic interfaces and the effect of the interfaces on spin-transport. Although spin-dependent effects have been widely studied in a variety of metals and conventional semiconductors, very little has been done in organic semiconductors for nanoscale device applications. There are two main advantages for using organic semiconductors, in particular pi-conjugated semiconductors for spin-electronics. Firstly, the spin relaxation time in these materials is relatively long, typically of the order of a microsecond at room temperature. This is caused by the light atoms from which these semiconductors are made and the small hyperfine interaction of the pi-electron wave function. The second advantage is that the main mechanism for carrier injection into organic semiconductors is by tunneling, which preserves spin states, so that the acute problem of conductance mismatch between the ferromagnetic spin aligner and the semiconductor is less troublesome. In addition, organic materials offer a wide range of work function values so that the tunnel barrier can be relatively easily engineered for spin-dependent low tunneling resistance, which is essential for high-density information storage and memory applications. Our feasibility study consists of two types of nanoscale devices. The first type is the planar spin-valve devices using pi-conjugated materials as a spacer. The objective is to explore low tunnel barrier spin-valves with high magnetoresistance. The second type is the organic spin light-emitting devices, where the electroluminescence emission will be modulated by an external magnetic field. The improved emitted light efficiency and magnetic field sensitivity are anticipated. These two types of devices involve with new material fabrication, fine lithography, and new material processing, which are highly non-trivial and of high risk. The PI and co-PI (Shi and Vardney) have expertise in magnetic tunnel junction materials and nanoscale device fabrication, polymer synthesis, organic crystal growth, magneto-transport, optics, and magneto-optics. Thus the two graduate students and two undergraduate students participating in this project will be well-trained in a rather interdisciplinary field.

该提案是根据NER类别中的纳米级科学与工程计划NSF 01-157提出的。 该提案侧重于（a）。使用铁磁eltrodes和Pi偶联的材料制造平面自旋阀门和发光设备； （b）有机/无机界面的研究以及界面对自旋传输的影响。尽管在各种金属和常规半导体中已经广泛研究了自旋依赖性效应，但在纳米级设备应用的有机半导体中，几乎没有做任何事情。 使用有机半导体有两个主要优点，特别是用于自旋电子学的PI偶联半导体。 首先，这些材料中的自旋松弛时间相对较长，通常是室温下微秒的顺序。 这是由从中产生这些半导体的光原子以及Pi-Electron波函数的较小的超精细相互作用引起的。 第二个优点是，将载体注入有机半导体的主要机制是通过隧道来保存旋转状态，因此铁磁性自旋对准器与半导体之间的电导不匹配的急性问题不那么麻烦。 此外，有机材料提供了广泛的工作功能值，因此隧道屏障可以相对容易地设计用于旋转依赖性的低隧道电阻，这对于高密度信息存储和内存应用至关重要。我们的可行性研究包括两种类型的纳米级设备。 第一种类型是使用PI偶联材料作为间隔者的平面自旋阀设备。 目的是探索具有高磁力磁性的低隧道屏障旋转阀。 第二种是有机自旋发光设备，其中电致发光发射将由外部磁场调节。 预计会提高发射光效率和磁场灵敏度。 这两种类型的设备涉及新的材料制造，精细的光刻和新的材料处理，这些处理高度不平整且风险很高。 PI和Co-Pi（Shi和Vardney）在磁性隧道连接材料以及纳米级装置制造，聚合物合成，有机晶体生长，磁通磁管，光学元件和磁电磁方面具有专业知识。 因此，两位研究生和两个参加该项目的本科生将在一个相当跨学科的领域进行良好的训练。