Wang Xu, Ma Ji, Zheng Wenhao, Osella Silvio, Arisnabarreta Nicolás, Droste Jörn, Serra Gianluca, Ivasenko Oleksandr, Lucotti Andrea, Beljonne David, Bonn Mischa, Liu Xiangyang, Hansen Michael Ryan, Tommasini Matteo, De Feyter Steven, Liu Junzhi, Wang Hai I, Feng Xinliang
College of Polymer Science and Engineering, State Key Laboratory of Polymer Material and Engineering, Sichuan University, 610065 Chengdu, P.R. China.
Centre for Advancing Electronics Dresden (cfaed) and Faculty of Chemistry and Food Chemistry, Technische Universität Dresden, 01062 Dresden, Germany.
J Am Chem Soc. 2022 Jan 12;144(1):228-235. doi: 10.1021/jacs.1c09000. Epub 2021 Dec 28.
Structurally precision graphene nanoribbons (GNRs) are promising candidates for next-generation nanoelectronics due to their intriguing and tunable electronic structures. GNRs with hybrid edge structures often confer them unique geometries associated with exotic physicochemical properties. Herein, a novel type of cove-edged GNRs with periodic short zigzag-edge segments is demonstrated. The bandgap of this GNR family can be tuned using an interplay between the length of the zigzag segments and the distance of two adjacent cove units along the opposite edges, which can be converted from semiconducting to nearly metallic. A family member with periodic cove-zigzag edges based on = 6 zigzag-edged GNR, namely , is successfully synthesized in solution through the Scholl reaction of a unique snakelike polymer precursor () that is achieved by the Yamamoto coupling of a structurally flexible S-shaped phenanthrene-based monomer (). The efficiency of cyclodehydrogenation of polymer toward is validated by FT-IR, Raman, and UV-vis spectroscopies, as well as by the study of two representative model compounds ( and ). Remarkably, the resultant exhibits an extended and broad absorption in the near-infrared region with a record narrow optical bandgap of 0.99 eV among the reported solution-synthesized GNRs. Moreover, exhibits a high macroscopic carrier mobility of ∼20 cm V s determined by terahertz spectroscopy, primarily due to the intrinsically small effective mass (* = * = 0.17 ), rendering this GNR a promising candidate for nanoelectronics.
结构精确的石墨烯纳米带（GNRs）因其引人入胜且可调节的电子结构，成为下一代纳米电子学的有前途的候选材料。具有混合边缘结构的GNRs通常赋予它们与奇异物理化学性质相关的独特几何形状。在此，展示了一种新型的具有周期性短锯齿边缘段的凹边GNRs。该GNR家族的带隙可以通过锯齿段的长度与沿相对边缘的两个相邻凹单元之间的距离之间的相互作用来调节，其可以从半导体转变为近金属。通过独特的蛇形聚合物前体（）的肖尔反应，在溶液中成功合成了一种基于 = 6锯齿边缘GNR的具有周期性凹-锯齿边缘的家族成员，即 ，该聚合物前体是通过结构灵活的S形菲基单体（）的山本偶联实现的。通过傅里叶变换红外光谱（FT-IR）、拉曼光谱和紫外可见光谱，以及对两种代表性模型化合物（ 和 ）的研究，验证了聚合物 向 的环脱氢效率。值得注意的是，在所报道的溶液合成GNRs中，所得的 在近红外区域表现出扩展且宽泛的吸收，光学带隙窄至0.99 eV。此外，通过太赫兹光谱测定， 表现出约20 cm V s的高宏观载流子迁移率，这主要归因于其固有的小有效质量（* = * = 0.17 ），使这种GNR成为纳米电子学的有前途的候选材料。
