(604a) Molecular Modeling of Solution-Processed Graphene Nanoribbons

Graphene nanoribbons (GNRs) combine the low dimensionality of graphene with band gaps sufficient for logic device application. By limiting the width of the GNRs to 1-2 nm, band gaps on the same order of magnitude as silicon can be reached (~1 eV). These GNRs can be fabricated through synthetic methods permitting atomically precise widths and edge geometries. In addition, functional groups can be appended to the edges that are spaced at regular intervals. These functional groups can be used to tune properties such as the dispersibility of the GNRs, their ability to self-assemble on a substrate or in solution, and their electronic characteristics.

However, it is difficult to experimentally determine what role these functional groups play to alter macroscopic properties of the material due because of the inherent complexity of these systems. For example, Interactions between the functional groups, graphene, and environment (solution and substrate) all play a significant role in the material’s overall behavior. Alternatively, molecular modeling techniques such as Molecular Dynamics (MD) can be used to deconvolute these various interactions so that an understanding can be built on how these different functional groups can alter GNR properties.

In this paper, MD will be used to investigate the properties of GNRs with uncharged functionalities in solution. In particular, the effects of different functionalities and solutions on the dispersibility and final aggregate morphologies of the GNRs will be discussed. Finally, the effects of these final aggregate morphologies on the GNRs’ electronic properties will be examined by comparing ab initio calculations to experimental measurements from fabricated devices.