UCLA Team develops a new synthetic method for graphene nanoribbons using only light and heat

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The significant invention by Yves Rubin & coworkers was recently reported in the first issue of Chem, a new journal published by Cell Press.

Prof. Yves Rubin and his coworkers conceived and executed a new synthetic approach to graphene nanoribbons, which are considered the next generation material for semiconductor logic or optoelectronic applications, but still very difficult to prepare on a large scale.

A tight collaboration with the group of Prof. Richard Kaner was essential to ascertain the outcome of this work through sophisticated characterization. 

Typically, graphene nanoribbons can only be synthesized in small quantities on specific metal surfaces under high vacuum or via multi-step organic reactions in solution.The new method developed by Rubin et al. is very simple and straightforward, as it only requires light and heat. It is carried out from an easily synthesized monomer precursor, which is converted to a well-defined polymer with light activation within the precursor’s crystals. After isolation of the polymers, they are readily converted to graphene nanoribbons with a width defined by the monomer precursor using relatively mild heating (below 300 ˚C). 

Graphene nanoribbons are viewed as the next generation material for nano-computing applications thanks to their well-defined band gap, which large-area graphene does not have. The graphene nanoribbons produced by Rubin et al. are 1.36 nm in width, which give rise to a band gap of 1.4 eV – a desirable value for these applications. 

Included research images:

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Conversion of a simple bis-naphthyl-butadiyne to a polydiacetylene (PDA) via crystal irradiation by light, followed by aromatization at 300 ˚C to a graphene nanoribbon (GNR). 

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Transmission electron microscope image of a bundle of graphene nanoribbons (GNRs). 

The article titled “Synthesis of Graphene Nanoribbons via the Topochemical Polymerization and Subsequent Aromatization of a Diacetylene Precursor” was published in the July 7, 2016 issue of Chem.

The co-first authors of the paper are graduate student Robert S. Jordan (Rubin) & alumna Dr. Yue Wang (Ph.D. ’14, Kaner).  Other co-authors are recent graduate Ryan D. McCurdy (B.S. ’16 Chemistry – Rubin), graduate student Michael T. Yeung (Kaner) and Kristofer L. Marsh (Kaner), X-Ray Diffraction Staff Scientist Saeed I. Khan (MIC), Profs. Richard B. Kaner and Yves Rubin.

To learn more about Rubin’s research, visit his group’s website.