CAREER: Molecular Scale Electronic Devices and Systems

传统的基于金属氧化物半导体（MOS）的集成电路的无情的缩小尺寸预计将由于基本的物理限制和与制造设施相关联的日益高昂的成本而减慢。 分子电子学的思想是，只有几个或甚至只有一个分子可以用来执行基本的电子功能，具有上级性能和大大降低成本的巨大希望。 作为一种自下而上的方法来制造纳米结构，分子电子学采用化学合成和组装来生产具有由分子线定义的关键尺寸的器件，因此可以消除与先进的光刻技术相关的成本。 这类器件充分利用了各种量子效应，如隧穿和构象跃迁等，因此可以提供比传统MOS器件更好的性能。这一计划的最终成功将坚定地确立分子电子学作为一种有趣而实用的技术，具有取代硅基电子学的巨大潜力。 我们希望生产集成电路中两个核心元件的分子电子学版本：晶体管和存储器。 我们的分子晶体管将拥有大约两纳米的沟道长度，比今天最先进的硅基晶体管小两个数量级。 我们也期望展示非易失性自旋相关的存储器与分子线作为主动组件。 这项技术将有可能制造出超小型的存储器，并为迄今为止的“经典”分子电子学增添了一个新的方向。 最后，我们希望展示一个新的计划，集成分子系统与碳纳米管作为互连。 这个计划也将有助于推进分子电子学的基本前沿。几个独特的特点区别于其他现有的程序在这个领域。我们将利用纳米孔技术来制造分子晶体管和自旋电子器件。 我们的小组是现有的两个掌握这种技术的小组之一（另一个是马克A。耶鲁大学的Reed Group，他目前专注于双端纳米孔器件）。 该技术可以使器件具有由分子线长度（~ 2nm）限定的通道长度和直径为~ 10 nm的器件区域。 这种纳米级器件为高密度集成提供了巨大的希望。我们将研究晶体管结构中的n型和p型分子线，使互补电路成为可能。 这个重要的问题到目前为止还没有被其他研究小组探索，因为显然很难。保证了拟议的研究和教育的紧密结合。 在整个项目中，将投入大量精力教育研究生和本科生，特别是代表性不足的学生。 研究活动也将被纳入纳米电子学和纳米技术类I开发。4.我们得到了NASA艾姆斯研究中心纳米技术中心合作者的全力支持。 Wendy Fan博士和她的同事们目前正将100%的时间投入到该计划的有机合成部分，NSF没有任何费用。 韩杰博士专注于所提出的分子器件的理论建模和模拟，同样，NSF不承担任何费用。总之，所提出的计划为未来的纳米级电子学带来了巨大的希望，并有很大的成功机会。 来自NSF的财政支持可以帮助我实现我的目标，在科学研究，学术咨询和教学中发展终身职业生涯是无价的。

The relentless down-scaling of the conventional metal-oxide-semiconductor (MOS) based integrated circuits is expected to slow down due to fundamental physical limitations and increasingly prohibitive cost associated with fabrication facilities. Molecular electronics, where the idea is that only a few or even just one molecule could be used to perform basic electronic functions, holds great promises for superior performance and substantially reduced cost. As a bottom-up approach to fabricate nanostructures, molecular electronics employs chemical synthesis and assembly to produce devices with critical dimensions defined by the molecular wires and hence can eliminate the cost associated with advanced lithography techniques. Such devices utilize various quantum effects such as tunneling and conformational transitions to their advantages and thus can deliver better performances than conventional MOS devices.The eventual success of this program will firmly establish molecular electronics as an intriguing and practical technology with great potential to replace silicon-based electronics. We expect to produce the molecular electronics version of two core elements in integrated circuits: transistors and memories. Our molecular transistors will possess a channel length around two nanometers, two orders of magnitude smaller than that of today's most advanced silicon-based transistors. We also expect to demonstrate nonvolatile spin-dependent memories with molecular wires as the active component. This technique will likely produce ultra-small memory devices and add a new direction to the by far "classical" molecular electronics. Finally we expect to demonstrate a new scheme for integrated molecular systems with carbon nanotubes as interconnects. This program will also serve to advance the fundamental forefronts of molecular electronics.Several unique features distinguish this program from other existing programs in this field.1. We will utilize the nanopore technique to produce molecular transistors and spin-electronic devices. Our group is one of two existing groups that have mastered this technique (the other being the Mark A. reed group at Yale, who is currently focusing on two-terminal nanopore devices). This technique can render devices with channel length defined by the molecular wire length (~ 2 nm) and device areas ~ 10 nm in diameter. Such nanoscale devices hold great promises for high-density integrations.2. We will investigate both n-type and p-type molecular wires in our transistor structures, making complementary circuitry possible. This important issue has by far being unexplored by other research groups due to the apparent difficulty.3. An intimate integration of the proposed research and education is guaranteed. Substantial effort will be devoted to educate both graduate and undergraduate students, especially the underrepresented, throughout this program. The research activities will also be integrated into the Nanoelectronics and Nanotechnology class I developed.4. We enjoy full support from our collaborators at the Nanotechnology Center of NASA Ames Research Center. Dr. Wendy Fan and her colleagues are currently devoting 100% of her time to the organic synthesis component of this program, at no cost to NSF. Dr. Jie Han is focusing on the theoretical modeling and simulations of the proposed molecular devices, again, at no cost to NSF.In conclusion, the proposed program holds great promises for future nanoscale electronics and has a great chance to succeed. The financial support from NSF can be invaluable in helping me to achieve my goal to develop a life-long career in scientific research, academic advising and teaching.