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.

该提案是为了响应 NER 类别中的纳米科学与工程计划、计划征集 NSF 01-157 而提交的。 该提案的重点是（a）。使用铁磁电极和π共轭材料制造平面自旋阀和发光器件； (b)有机/无机界面以及界面对自旋输运影响的研究。尽管自旋相关效应已在各种金属和传统半导体中得到广泛研究，但在用于纳米级器件应用的有机半导体方面却做得很少。 使用有机半导体，特别是用于自旋电子学的π共轭半导体有两个主要优点。 首先，这些材料的自旋弛豫时间相对较长，在室温下通常为微秒量级。 这是由制造这些半导体的轻原子和π电子波函数的小超精细相互作用引起的。 第二个优点是载流子注入有机半导体的主要机制是通过隧道效应，这保留了自旋态，因此铁磁自旋对准器和半导体之间电导失配的尖锐问题不那么麻烦。 此外，有机材料提供了广泛的功函数值，因此可以相对容易地设计隧道势垒来实现自旋相关的低隧道电阻，这对于高密度信息存储和存储器应用至关重要。我们的可行性研究包括两种类型的纳米级设备。 第一类是使用π共轭材料作为间隔物的平面自旋阀器件。 目的是探索具有高磁阻的低隧道势垒旋转阀。 第二种是有机自旋发光器件，其中电致发光发射将受到外部磁场的调制。 预计发射光效率和磁场灵敏度将得到改善。 这两类器件涉及新材料制造、精细光刻和新材料加工，非常重要且风险很高。 PI 和联合 PI（Shi 和 Vardney）在磁隧道结材料和纳米级器件制造、聚合物合成、有机晶体生长、磁输运、光学和磁光方面拥有专业知识。 因此，参与该项目的两名研究生和两名本科生将在跨学科领域接受良好的培训。