Orbitally Matched Edge-Doping in Graphene Nanoribbons
Orbitally Matched Edge-Doping in Graphene Nanoribbons
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DOI：
10.1021/jacs.7b11886
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发表时间：
2018-01-17
影响因子：
15
通讯作者：
Fischer, Felix R.
中科院分区：
文献类型：
--
作者：
Durr, Rebecca A.;Haberer, Danny;Fischer, Felix R.
沿沿着衬于自下而上合成的人字形石墨烯纳米带（cGR）的边缘的凸形突出部并入的一系列三角形平面N-、O-和S-掺杂剂原子引起导带和价带边缘态的能量的特征性偏移，其中带隙沿着显著减小，每个单体每个掺杂剂原子高达0.3eV。扫描探针光谱和密度泛函理论计算的组合表明，掺杂剂原子和cGNR骨架之间的电荷转移的方向和大小由诱导效应主导，并遵循电负性的预期趋势。引入具有三角平面几何形状的杂原子掺杂剂确保了以掺杂剂原子为中心的p轨道孤对与cGNR骨架的扩展π系统的有效重叠，有效地扩展了共辄长度。我们的工作展示了一种广泛可调的方法，用于先进电子应用的石墨烯纳米结构的带隙工程。
A series of trigonal planar N-, O-, and S-dopant atoms incorporated along the convex protrusion lining the edges of bottom-up synthesized chevron graphene nanoribbons (cGRs) induce a characteristic shift in the energy of conduction and valence band edge states along with a significant reduction of the band gap of up to 0.3 eV per dopant atom per monomer. A combination of scanning probe spectroscopy and density functional theory calculations reveals that the direction and the magnitude of charge transfer between the dopant atoms and the cGNR backbone are dominated by inductive effects and follow the expected trend in electronegativity. The introduction of heteroatom dopants with trigonal planar geometry ensures an efficient overlap of a p-orbital lone-pair centered on the dopant atom with the extended pi-system of the cGNR backbone effectively extending the conjugation length. Our work demonstrates a widely tunable method for band gap engineering of graphene nanostructures for advanced electronic applications.