Redox-switchable devices based on functionalized graphene nanoribbons

Abstract

The possibility of tuning the electronic properties of graphene by tailoring the morphology at the nanoscale or by chemical functionalization opens interesting perspectives towards the realization of devices for nanoelectronics. Indeed, the integration of the intrinsic high carrier mobilities of graphene with functionalities that are able to react to external stimuli allows in principle the realization of highly efficient nanostructured switches. In this paper, we report a novel approach to the design of reversible switches based on functionalized graphene nanoribbons, operating upon application of an external redox potential, which exhibit unprecedented ON/OFF ratios. The properties of the proposed systems are investigated by electronic structure and transport calculations based on density functional theory and rationalized in terms of valence-bond theory and Clar's sextet theory.

Tuning aromaticity patterns and electronic properties of armchair graphene nanoribbons with chemical edge functionalisation

“…For instance, Selli et al have proposed redox-switchable devices in a recent work, where controlling of aromaticity patterns with different functional groups at the edge enables the switching behaviour. 34 GNRs belong to a new class of one-dimensional materials whose edges are easily accessible to chemical functionalisation as a suitable way to modify their properties. 14,34 In this regard, hydrogen termination of dangling bonds is the usual approach in molecular modelling of carbon nanomaterials, but other types of edge functionalisation are equally accessible to computational chemistry and it provides valuable data concerning the chemical modification of these materials.…”

A Computational Predictive Approach for Controlling the Morphology of Functional Molecular Aggregates on Substrates

“…At low target coverages (about 0.68 mol nm −2 , corresponding to 68 molecules on the equilibrated graphene substrate of about 10 × 10 nm), simulations of the formation of the interface between PTCDI‐C13 and graphene, carried out with the pristine interaction potential ( μ = 1) in kinetic conditions (see Table S1, Supporting Information), show a clear propensity to formation of disordered molecular aggregates in the flat‐lying configurations ( γ = 90°, see Figure S2, Supporting Information). The occurrence of the flat‐lying configuration, favored by the π‐stacking interactions between the PTCDI‐C13 core and the underlying honeycomb lattice with partial aromatic character, has been largely observed in the growth of perylene derivatives on graphitic substrates at low coverages . At the same coverage, aggregation in thermodynamic conditions (see Table S1, Supporting Information) induces long‐range ordering at the interface, leading to a closely packed (herringbone‐like) planar interfacial layer (IL) of PTCDI‐C13 molecules on graphene, as shown in Figure .…”

Toward Real Setting Applications of Organic and Perovskite Solar Cells: A Comparative Review

“…[ 203,204 ] Recent research work has demonstrated the potential of low‐dimensional carbon nanostructures, such as graphene, carbon nanotubes, or composites, to realize highly conductive and transparent electrodes for solar cells. [ 205,206 ]…”

“…[203,204] Recent research work has demonstrated the potential of low-dimensional carbon nanostructures, such as graphene, carbon nanotubes, or composites, to realize highly conductive and transparent electrodes for solar cells. [205,206] Nevertheless, wet processes can unleash their full potential in the fabrication of electrodes based on organic molecular or polymer materials. The relatively low conductivity of organic materials is usually alleviated by doping the electrode, a process that, however, can limit the stability of the device.…”