Emerging Bottom‐Up Strategies for the Synthesis of Graphene Nanoribbons and Related Structures

Abstract

The solution‐phase synthesis is one of the most promising strategies for the preparation of well‐defined graphene nanoribbons (GNRs) in large scale. To prepare high quality, defect‐free GNRs, cycloaromatization reactions need to be very efficient, proceed without side reaction and mild enough to accommodate the presence of various functional groups. In this Minireview, we present the latest synthetic approaches for the synthesis of GNRs and related structures, including alkyne benzannulation, photochemical cyclodehydrohalogenation, Mallory and Pd‐ and Ni‐catalyzed reactions.

Synthesis of Nonplanar Graphene Nanoribbon with Fjord Edges

“…Graphene nanoribbons (GNRs), quasi-one-dimensional (1D) cutouts of graphene, have been highlighted as promising candidates for next-generation electronics because their intriguing electronic properties can be precisely tuned by their chemical structures. 1 − 5 The development of cutting-edge synthetic methods, especially bottom-up synthesis, 6 − 8 utilizing on-surface and solution-mediated reactions, has delivered structurally defined GNRs with various edge structures, including armchair, 9 − 11 zigzag, 12 cove, 13 and gulf. 14 Furthermore, the peripheral features significantly alter the electronic properties of GNRs.…”

Sensors Based Upon Nanowires, Nanotubes, and Nanoribbons: 2016–2020

“…Other common fabrication methods used for graphene NR sensors include bottom-up chemical synthesis and CVD. ,, Bottom-up chemical synthesis relies upon multistep organic syntheses that start with alkyne, alkene, or halogenated precursors that are assembled into a polymer that serves as the synthetic precursors to graphene nanoribbons. ,, CVD bottom-up synthesis relies on graphene formation induced by the thermal decomposition of the organic polymers . Compared to top-down synthetic methods, bottom-up synthetic methods offer greater uniformity and control over the graphene NR edges.…”

“…Graphene, , layered transition metal dichalcogenides, and black phosphorus , belong to a family of 2D materials in which the atoms are arranged in a layered, sheet-like structure. Individual layers can be exfoliated from the bulk and typically show interesting electrical properties that depart significantly from that of the bulk material …”

“…Edge defects in graphene have higher chemical reactivity and can impart unique electronic/spintronic properties that are observable when graphene is formed into nanoribbons . Graphene NRs narrower than 10 nm are particularly of interest as quantum confinement of the electrons opens a band gap, increasing the potential applications of graphene in electronics and chemiresistive sensing. ,, …”

Single Crystalline 2D Material Nanoribbon Networks for Nanoelectronics

“…[12][13][14] Despite all the possibilities that 2D material-based NRs hold, their sufficient quality, narrow widths, density, controlled edges, and high yield remain as technological challenges for realistic applications. The most widely used preparation methods are bottom-up chemical synthesis [15][16][17][18] and top-down lithography. [19][20][21] Chemical synthesis of NRs offers excellent edge control; however, the device channels suffer from electrical percolation issues and high junction (node) resistances.…”