Porphyrin-Graphene Nanoribbon (PGNR) Conjugates: Solution Syntheses and Properties

近年来，石墨烯纳米带因其高载流子迁移率和可调带隙而引起了人们的极大兴趣，这使其有可能用作碳基半导体。可控地引入结构缺陷，如非六方环和杂原子，是调整其光电性能的有效策略。在所有构建模块中，卟啉是包含这两种因素的理想候选。将卟啉与GNR结合在一起，有望创造出“超级材料”，可以从每种成分的优势中获益。申请人在纳米石墨烯合成方面有超过五年的工作经验，并在博士期间开发了一种有效的将石墨烯分子与卟啉融合的方法。在本提案中，申请人将应用先前的方法合成纵向扩展卟啉熔融石墨烯纳米带（pgnr），并使用跨学科方法研究其光电特性。具体而言，将设计和合成两种新型结构复杂的pgnr：一种是将卟啉基团嵌入到9原子宽GNR的主链中，另一种是将卟啉单元融合到字形GNR的锯齿边缘上。本课题将解决三个主要问题：1)如何合成具有原子精度结构的pgnr ？由于gnr的精确结构对其在设备中的电子特性和性能至关重要，因此对其化学结构进行原子精确控制至关重要。本文将采用溶液合成方法，即合理设计和合成单体构件，并采用高效聚合方法；2) pgnr的特性及其相对于所有碳基GNR的优势是什么？为了回答这个问题，我们将合成正常的9- agnr /Chevron gnr和pgnr。将对它们的光电性能和电荷迁移率进行并行比较和研究，这将反映卟啉掺杂的真实效果；3)这些新的pgnr可以用于什么？这两种pgnr都是高度共轭的，应该具有低能隙和高电荷迁移率。因此，他们将尝试制造单分子场效应晶体管器件。另一方面，卟啉核可以与磁性离子配合，这将使它们在制造存储器件和自旋电子器件方面具有前景。该项目的研究结果不仅拓宽了我们对gnr基本性质的理解，而且为其未来在分子器件中的应用铺平了道路。

Graphene nanoribbons (GNRs) have attracted tremendous interest in recent years for their high charge carrier mobility and adjustable bandgap, making them potential to be used as carbon-based semiconductors. Controllable introduction of structural defects, such as non-hexagonal rings and heteroatoms, represents a useful strategy to tune their optoelectronic properties. Among all building blocks, porphyrin is an ideal candidate containing both of these two factors. Combining porphyrin with GNR holds great promise to create “super material”, which could benefit from advantages of each component. The applicant has over five years’ working experience in nanographene synthesis and developed one efficient method to fuse graphene molecules with porphyrin during his PhD. In this proposal, the applicant will apply the previous method to synthesize longitudinal extended porphyrin-fused graphene nanoribbons (PGNRs) and investigate their optoelectronic properties using interdisciplinary methodology. Specifically, two new types of structurally complex PGNRs will be designed and synthesized: one has porphyrin moieties embedded in the backbone of 9-atom wide GNR and the other has porphyrin units fused to the zigzag edges of chevron type GNR. Three main questions will be addressed in the current project: 1) How to synthesize PGNRs with atomically precise structures? As the exact structures of GNRs are crucial for their electronic properties and performances in devices, it’s vital to hold atomically precise control over their chemical structures. Here, a solution synthesis method will be applied, which involves rational design and synthesis of monomer building blocks and applying efficient polymerization method; 2) What are the properties of PGNRs and their advantages over their all carbon-based GNR counterparts? To answer this question, we will synthesize both normal 9-AGNRs/Chevron GNRs and PGNRs. Their optoelectronic and charge mobility properties will be compared and investigated in parallel, which will reflect the real effect of porphyrin doping; 3) What could these new PGNRs be used for? Both of these two PGNRs are highly conjugated and should have low energy gap and high charge mobility. So, they will be tried to fabricate single-molecule field-effect transistor devices. On the other hand, the porphyrin core could be coordinated with magnetic ions, which will make them promising for fabricating memory devices and spintronic devices. The results from this project will not only broaden our understanding of fundamental properties of GNRs, but also pave the way for their future applications in molecular devices.