NER: Hybrid Organic-Inorganic Devices for Future Spintronics Applications

NER：用于未来自旋电子学应用的有机-无机杂化器件

• 批准号: 0210281
• 负责人: Elisabeth Gwinn
• 金额: --
• 依托单位: University of California-Santa Barbara
• 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 2004-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0210281&HistoricalAwards=false
• 关键词: NER; Hybrid; Organic; Inorganic; Devices

This proposal was received in response to the Nanoscale Science and Engineering initiative, Program Solicitation NSF 01-157, in the NER category. The proposal focuses on testing the feasibility of using self-assembly of organic monolayers onto inorganic substrates to control spin phenomena, namely magnetism. The work is a collaboration between the Gwinn group at UCSB, which has expertise in semiconductor physics, and the Naaman group at the Weizmann Institute, which has expertise in the assembly of organized, organic thin films (QOTF) onto inorganic substrates. In these hybrid devices, organic molecules with large electric dipole moments chemisorb onto an inorganic substrate, forming an organized, close-packed dipole sheet. The energetics of forming the adsorbate favors transfer of electrons between the organic molecules and the substrate, somewhat similar to the effect of gates in field-effect devices, but without the need for a gate or gate insulator. This chemically-induced charge transfer modifies the electronic properties of both adsorbate and substrate.The proposed feasibility experiments will test for spin-related phenomena in hybrid devices of organized organic adsorbates on inorganics. The advantages of using organic material is the large versatility in properties that can be tailored relatively easily, its low cost, and the ease of production due to self-assembling processes that can replace expensive high resolution lithography. The enormous variety of organic molecules that self-assemble provides a chemical ~knob" that may make possible new classes of organic/inorganic spintronic devices.Two lines of investigation will be pursued during this year-long project: studies of chemical manipulation of the magnetic properties of GaAs-based semiconductor devices via the organic adsorbate; and studies of the magnetic properties of organic inonolayers of chiral molecules on non-magnetic substrates. Ferromagnetic GaAs heterostructures with near-surface Mn-doped layers will be covered with OOTF to test the feasibility of chemically controlling magnetism in ferromagnetic semiconductors. The effects of the OOTF will be investigated by magnetometry and by magnetotransport measurements. Adsorption of OOTF onto the sidewalls of non-magnetic GaAs/A1GaAs superlattices will be used to attempt to modify the sheath of edge states that appears in the quantum Hall regime. Signatures of the effects of the OOTF would appear in low-temperature magnetotransport experiments. Studies of chiral OOTF will investigate further their previously observed magnetic properties, when adsorbed onto Au; and whether the chiral QQTF retain their magnetic properties when adsorbed onto GaAs.

该提案是响应纳米尺度科学与工程倡议，项目招标NSF 01-157，在NER类别。该提案的重点是测试在无机基底上使用有机单层自组装来控制自旋现象（即磁性）的可行性。这项工作是由UCSB的Gwinn小组和Weizmann研究所的Naaman小组合作完成的，前者具有半导体物理方面的专业知识，后者具有在无机衬底上组装有组织有机薄膜（QOTF）的专业知识。在这些混合装置中，具有大电偶极矩的有机分子化学吸附到无机衬底上，形成有组织的紧密排列的偶极子片。形成吸附质的能量学有利于电子在有机分子和衬底之间的转移，有点类似于场效应器件中的栅极效应，但不需要栅极或栅极绝缘体。这种化学诱导的电荷转移改变了吸附物和衬底的电子性质。提出的可行性实验将测试有组织有机吸附在无机物上的杂化装置中的自旋相关现象。使用有机材料的优点是其具有较大的多功能性，可以相对容易地定制，其成本低，并且由于自组装过程可以取代昂贵的高分辨率光刻而易于生产。各种各样的自组装有机分子提供了一个化学“旋钮”，可能使新型的有机/无机自旋电子器件成为可能。在这个为期一年的项目中，将进行两方面的研究：通过有机吸附物对gaas基半导体器件磁性的化学操作的研究；以及手性分子在非磁性底物上的有机分子膜的磁性研究。用OOTF覆盖具有近表面mn掺杂层的铁磁GaAs异质结构，以测试在铁磁半导体中化学控制磁性的可行性。OOTF的影响将通过磁强计和磁输运测量来研究。OOTF吸附在非磁性GaAs/A1GaAs超晶格的侧壁上，将被用来尝试改变出现在量子霍尔体系中的边缘态鞘。OOTF效应的特征将出现在低温磁输运实验中。手性OOTF的研究将进一步研究它们先前观察到的吸附在Au上的磁性；手性QQTF吸附在砷化镓上时是否保持磁性。