Quasiparticles in Graphene Nanoribbon Heterojunctions: Insights from a Simplified One-Dimensional Model

Graphene nanoribbons (GNRs) are promising candidatesfor next-generationnanoelectronics because of their incredible structural versatility.They are behind numerous breakthroughs in optoelectronics where chargetransport is pivotal. Recently, the development of heterojunctions(HJs) boosted this potential by mixing the properties of two GNRsinto a single system. However, there are still a variety of junctionsto be explored. In this work, we propose a simplified modeling ofthe charge transport in cove-type HJs by considering the nanoribbonsas one-dimensional polymers. The GNRs are simulated using the one-dimensionaltight-binding model Hamiltonian with lattice relaxation, which isparametrized by mapping the HJ structure into a chain that bears polaronswith the same properties as the carriers hosted in nanoribbons. Resultsindicate that, depending on the GNR structure, the parametrized electron-phononconstant and sites' masses may vary 5.9-4.6 eV/& ANGS;and 52-5 u, respectively. Closer analysis of these variationsrevealed the existence of HJ families in which the hosted polaronsare similar. This symmetry became apparent only after reducing thedimensionality of the dynamics mechanism through our approach. Themodeling is readily applicable for any HJ, offering an alternativeframework to investigate the effects of junction formation on chargetransport through a clearer picture.

Automated summary

This paper proposes a simplified model to simulate charge transport in cove-type heterojunctions by considering nanoribbons as one-dimensional polymers. The results indicate that the electron-phonon constant and sites' masses can vary depending on the nanoribbon structure. This approach provides a clearer picture to investigate the effects of junction formation on charge transport.