Graphene- and Metal-based Atomically Precise Nanoelectronics

技术支持：该项目的目标是开发具有原子级精确边缘和边界的石墨烯和金属基纳米结构的制造方法，并对这些样品进行全面的变温磁输运测量，以与理论预测进行比较。其他目标包括科学探索石墨烯和金属基器件，所有三个空间维度都小于10 nm，以及由此量子限制产生的现象，包括方向和宽度依赖的能隙的开放，由于无质量石墨烯电荷载流子引起的不寻常的量子限制效应，以及自旋电子应用感兴趣的石墨烯的半金属行为。该项目的长期目标是：1）精确控制此类样品的制造，以避免边缘缺陷（空位）等的有害影响; 2）详细了解其物理特性，以便充分利用其电子特性。该项目的第二个主题是使用由于施加电流，磁场，温度梯度和蒸汽流的质量传输过程，以实现原子级精确的纳米纤维。原子尺度质量迁移效应的详细研究将对理解纳米器件的老化和失效产生广泛的影响，因为两者密切相关。原子级精确纳米制造的方法将基于金属收缩的反馈控制电迁移。该方法可以使得能够产生具有原子级平滑边缘的金属掩模，该金属掩模将被用于限定尺寸上所有三个维度都小于10 nm的石墨烯纳米带。金属纳米颗粒将用于将石墨烯催化蚀刻成纳米带，其边缘平行于碳晶格的明确定义的晶轴。石墨烯点接触将通过直接FCE形成。金属纳米线与集成的接触和原子级精确的侧壁将通过控制在FCE过程中发展的热梯度来制造。微米长的纳米线与原子级光滑的侧壁将寻求通过执行FCE过程与集成加热器提供的热梯度的同时独立控制。热梯度及其演变的细节将以纳米级空间分辨率和100微秒测量。- 1 ms时间分辨率。非技术性：该项目涉及电子/光子材料科学领域的基础研究问题，具有高度的技术相关性。研究和教育与教育，推广，国际合作，并在科学和工程相关领域的影响的重点相结合。培训将提供给研究生，本科生和高中生在一个充满活力和跨学科的研究环境。PI的推广和教育工作将包括与宾夕法尼亚科学教师研究所建立伙伴关系，为其教师毕业生提供研究经验，并开发短期课程，以增加高中科学教师的内容知识。费城的K-12社区将通过参与一年一度的NanoDay@PENN，包括来自该组织的技术海报和适合普通观众的演示文稿。将通过与NanoAFNET（纳米科学非洲网络）的国际伙伴关系加强研究基础设施;该项目每年将接待多达三名在纳米电子学和纳米材料领域有研究兴趣的科学家。

Technical: The goal of the project is to develop fabrication methods for graphene- and metal-based nanostructures with atomically precise edges and boundaries, and to perform comprehensive variable-temperature magnetotransport measurements on these samples for comparison with theoretical predictions. Other goals include the scientific exploration of graphene- and metal-based devices with all three spatial dimensions smaller than 10 nm, and phenomena derived from this quantum confinement, including the opening of an orientation- and width-dependent energy gap, unusual quantum confinement effects due to the massless graphene charge carriers, and half-metallic behavior of graphene of interest for spintronic applications. Long-term objectives of the project are 1) precise control over the fabrication of such samples so that the deleterious effects of edge defects (vacancies) and the like can be avoided, and 2) a detailed understanding of their physics so that the full power of their electronic properties can be harnessed. A second theme of the project is the use of mass transport processes due to applied currents, magnetic fields, temperature gradients, and vapor flow to achieve atomically precise nanofabrication. This detailed investigation of atomic scale mass migration effects will have broad impact on the understanding of aging and failure of nanoscale devices, as the two are closely linked. Methods of atomically precise nanofabrication will be based on Feedback Controlled Electromigration of metal constrictions. This method may enable creation of metal masks with atomically smooth edges that will be used to define graphene nanostrips with all three dimensions smaller than 10 nm in size. Metal nanoparticles will be used to catalytically etch graphene into nanoribbons whose edges run parallel to well defined crystal axes of the carbon lattice. Graphene point contacts will be formed by direct FCE. Metal nanowires with integrated contacts and atomically precise sidewalls will be fabricated by controlling thermal gradients that develop during FCE. Micrometer-long nanowires with atomically smooth sidewalls will be sought by performing the FCE process with simultaneous independent control of thermal gradients provided by integrated heaters. Details of the thermal gradients and their evolution will be measured with nanoscale spatial resolution and 100 microsec. - 1 ms time resolution. Non-technical: The project addresses basic research issues in a topical area of electronic/photonic materials science with high technological relevance. Research and education are integrated with emphasis in education, outreach, international collaboration, and impact on related fields in science and engineering. Training will be provided to graduate students, undergraduates, and high school students in a dynamic and interdisciplinary research environment. Outreach and education efforts by the PIs will include a partnership with the Penn Science Teachers Institute to provide research experiences for their teacher graduates and to develop short courses to increase the content knowledge of high school science teachers. Philadelphia's K-12 community will be engaged through participation in the annual NanoDay@PENN, including technical posters from the group and presentations appropriate for a general audience. Research infrastructure will be enhanced through an international partnership with NanoAFNET, the Nanosciences African Network; the project will host up to three scientists per year with research interests in the area of nanoelectronics and nanomaterials.