Charge localization and hopping in a topologically engineered graphene nanoribbon

Abstract

Graphene nanoribbons (GNRs) are promising quasi-one-dimensional materials with various technological applications. Recently, methods that allowed for the control of GNR’s topology have been developed, resulting in connected nanoribbons composed of two distinct armchair GNR families. Here, we employed an extended version of the Su-Schrieffer-Heeger model to study the morphological and electronic properties of these novel GNRs. Results demonstrated that charge injection leads to the formation of polarons that localize strictly in the 9-AGNRs segments of the system. Its mobility is highly impaired by the system’s topology. The polaron displaces through hopping between 9-AGNR portions of the system, suggesting this mechanism for charge transport in this material.

Preparation, Bandgap Engineering, and Performance Control of Graphene Nanoribbons

“…The result provided both theoretical and experimental instructions on topological management of the bandgap size, as the biggest challenge here was to synthesize a precise structure of predesigned GNR. Nevertheless, carrier mobility for 7/9-AGNR superlattice was severely suppressed to 0.1 cm 2 V –1 s –1 , indicating a hindered charge transport manner in such a superlattice . Coincidently, at the same time, Gröning et al published their findings on the manipulation of different quantum phases (with different Z 2 values) .…”

Regulating Polaron Transport Regime via Heterojunction Engineering in Cove‐Type Graphene Nanoribbons

“…Under this formalism, charge transport is modeled as the drifting of a localized collective excitation along the lattice. The use of similar approaches yielded insightful results for other edge symmetries, [39,[41][42][43]50] polymeric systems [40,44,51] and crystalline arrangements under the Holsteinpolaron modeling for intermolecular transport. [52][53][54] In this work, we assessed the effects on transport and electronic properties due to the heterojunction engineering of cove-type graphene nanoribbons with different zigzag segments as building blocks.…”

“…The use of similar approaches yielded insightful results for other edge symmetries and polymeric systems. [39][40][41][42][43][44] Several modelings were developed to simulate intramolecular charge transport. For instance, DFT-based studies use the deformation potential theory combined with the semiclassical Boltzmann transport equation to estimate the carrier's effective mass and mobility in a free carrier picture that only considers the acoustic phonons.…”

“…For instance, DFT-based studies use the deformation potential theory combined with the semiclassical Boltzmann transport equation to estimate the carrier's effective mass and mobility in a free carrier picture that only considers the acoustic phonons. [45][46][47] Although widely diffused, the approach does not explicitly address inner transport mechanisms such as polaron-phonon collisions [21,42,44,48] and quasiparticle formation [40,43,49] when there is a tight coupling between lattice and electronic phenomena. An alternative lies in nonadiabatic model Hamiltonians like the Su-Schrieffer-Heeger (SSH) model, which can represent the intrinsic bound nature of the quasiparticles.…”

Charge Density Wave Transport in Porous Graphene Nanoribbons

“…In summary, we described charge density waves transport mechanism in porous graphene nanoribbons of different widths. So far, the literature had reported quasiparticles such as polarons and bipolarons to be responsible for the transport in graphene-based nanoribbons [28,65,[65][66][67]. By considering porosity, the one dimensional character that is typical of systems which exhibits such phenomena is present.…”