二维有序分子聚合结构的表面制备及其电子学性质研究

Two-dimensional (2D) polymerized frameworks have attracted much attention because of their potential applications in physical and chemical sciences, as well as information and energy technologies. On-surface synthesis of low-dimensional nanostructure via polymerization of surface-supported molecules on the basis of ultra-high vacuum (UHV) techniques has been fast developed due to the unique advantages of UHV methods. However, there still have some key problems to be solved before we can get large-area highly-ordered 2D polymerized network. In this proposal, we plan to study the preparation and characterization of on-surface of 2D polymerized molecular framework with the aid of UHV techniques and scanning tunneling microscopy. Surface poision by reaction residue and self-corrected issues which influences the quality of 2D polymerization, are to be studied and solved by developing new source techniques and controlling methods. We will explore new reaction mechanism and routes including ultra-violet radiation etc. to finally realize large-area highly-ordered 2D molecular frameworks. We will also develop methods for isolating and transferring the synthesized 2D framework, and study their electronic properties by making prototype devices. The proposed research will combine physical techniques, chemical reactions and material synthesis to form a characterful research direction, and are expected to provide scientific inspirations and research basis for design and fabrication of practical materials and devices of 2D molecular frameworks.

二维聚合结构因其在物理、化学、信息和能源等领域的潜在应用成为当前表面物理化学领域的一个重要研究方向。基于超高真空的方法通过表面上分子的聚合来制备低维纳米结构具有独特的优越性，在近年来得到了迅速发展，然而要制备大面积有序的二维分子聚合结构仍然存在亟待解决的难点。在本申请项目中，我们拟开展基于超高真空技术和扫描隧道显微学的表面二维分子聚合结构的制备和性质研究。我们拟发展新的分子源和超高真空控制手段，解决残留物毒化表面和难以自修复等影响聚合质量的关键问题，通过原位紫外光源等手段，探索新的表面聚合反应路线和机制，以实现大面积有序分子聚合结构。我们拟开展的上述研究将物理方法和化学反应有机结合起来，有望形成一个有特色的表面物理化学研究方向，为阐明表面分子聚合的机制并实现有序的聚合提供研究基础。

项目针对单个平面大环分子及其聚合结构开展了相关研究并取得了一系列研究成果，主要包括：卟啉类分子聚合结构中的电子态调制；成功构造出分子内自旋耦合的人造分子-原子聚合结构；成功制备出了表面有机含卤分子与碱金属原子组成的配合二维金属有机网格结构，这是第一次发现分子中的卤素原子和碱金属原子之间形成的弱的卤-碱键可以用于构建大面积高度有序的二维分子聚合结构；利用金属表面的乌尔曼反应制备出了一维金属有机分子链状结构和一维聚苯结构，并在此基础上，利用表面重构制备出了大长宽比的石墨烯纳米条带；自行设计和合成了一种含溴分子并实现了其表面聚合，成功制备出了锯齿边的石墨烯纳米条带；利用贵金属表面脱卤的特性，成功制备出了具有完全平面结构的单层二维锡烯。项目执行期间已发表SCI论文2篇，其中一篇被选为Appl. Phys. Lett.封面文章和特色文章，另有多篇在投。培养博士研究生1名，国内学术会议邀请报告1人次，参加国际学术会议口头报告1人次。