CAREER: Saturated and Unsaturated Silicon for Single-Molecule Electronics

在化学部化学结构、动力学和机制B项目的支持下，加州大学河滨分校(UCR)化学系的Timothy Su正在开发最小长度尺度(即分子)的硅基电子产品。硅是现代微电子和新兴量子电子技术的标志性材料。随着硅电子产品越来越小型化，了解如何设计和控制分子长度尺度的硅结构以提供定制的电子性能变得越来越重要。中心假设是，通过控制分子主干的结构，硅基分子电路可以成为高阻、高导电或可电子开关的电路，其程度超过了当前的分子电子技术。教育活动的重点是吸引和留住从小学到大学的STEM(科学、技术、工程和数学)方面的弱势学生和任职人数不足的学生。为了实现这一目标，将利用学生创建的社交媒体视频：(1)改善学习结果，缩小UCR学生在STEM课程的起点上的成就差距，(2)创建一个网络基础设施，以揭开化学概念和STEM职业的神秘面纱，(3)通过硅材料实验吸引当地5年级和6年级学生学习科学，以及(4)扩大对化学研究的参与。这些活动主要针对加州大学河滨分校的学生的需求，加州大学河滨分校是一家指定的西班牙裔服务机构(HSI)，那里超过50%的学生是佩尔助学金获得者，也是他们家庭中第一个进入四年制大学的学生。这项建议描述了利用扫描隧道显微镜断裂结(STM-BJ)方法研究共轭分子硅的合成、功能化和集成到单分子电路中。它将：(1)探索Ge原子的掺入和团簇二聚化对双环低聚硅烷绝缘体中破坏性量子干涉(DQI)的影响；(2)使用机械刺激来促进或破坏聚硅烷主干内的弱分子内键相互作用，以访问可逆的电导开关；以及(3)将不饱和硅分子作为一类未被探索的纳米电子材料来探测，预计其导电性将比其有机类似物高几个数量级。这些努力旨在为首席研究员探索被称为主群分子电子学的新兴工作领域的计划奠定基础。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

With support from the Chemical Structure, Dynamics & Mechanisms B Program of the Chemistry Division, Timothy Su of the Department of Chemistry at the University of California, Riverside (UCR) is developing silicon-based electronics at the smallest length scales (i.e., molecules). Silicon is the hallmark material of modern microelectronics and emerging quantum electronic technologies. With silicon electronics becoming increasingly miniaturized, it is ever important to understand how the structure of silicon at molecular length scales can be designed and controlled to give tailored electronic properties. The central hypothesis is that by controlling the structure of the molecular backbone, silicon-based molecular circuits can be made to be highly resistive, highly conducting, or electronically switchable to extents that outperform current molecular electronic technologies. The educational activities focus on attracting and retaining disadvantaged and underrepresented students in the STEM (science, technology, engineering and mathematics) pipeline from the elementary school level to the university level. Toward this goal, student-created social media videos will be leveraged to: (1) improve learning outcomes and close the achievement gap for UCR students at the entry point of their STEM coursework, (2) create a cyberinfrastructure to demystify chemical concepts and STEM careers, (3) engage local 5th and 6th grade students in science through silicon materials experiments, and (4) broaden participation in chemical research. These activities heavily target the needs of students at UC Riverside, a designated Hispanic Serving Institution (HSI), where over fifty percent of students are Pell Grant recipients and the first in their families to attend a 4-year college.This proposal describes the synthesis, functionalization, and integration of conjugated molecular silicon into single-molecule circuits studied with a scanning tunneling microscopy break-junction (STM-BJ) approach. It will: (1) explore the impact of Ge-atom incorporation and cluster dimerization on destructive quantum interference (DQI) in bicyclic oligosilane insulators, (2) use mechanical stimuli to promote or disrupt weak intramolecular bonding interactions within the polysilane backbone to access reversible conductance switches, and (3) probe unsaturated silicon molecules as an unexplored class of nanoelectronic materials anticipated to be several orders of magnitude more conductive than their organic analogs. These efforts are aimed at establishing the foundation of the principal investigator’s program to explore an emerging area of work termed main group molecular electronics.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.