Electrochemical Control of Charge Current Flow in Nanoporous Graphene

Abstract

During the last decade, on‐surface fabricated graphene nanoribbons (GNRs) have gathered enormous attention due to their semiconducting π‐conjugated nature and atomically precise structure. A significant breakthrough is the recent fabrication of nanoporous graphene (NPG) as a 2D array of laterally bonded GNRs. This covalent integration of GNRs could enable complex electronic functionality at the nanoscale; however, for that, it is crucial to externally control the electronic coupling between GNRs within NPGs, which, to date, has not been possible. Using quantum chemical calculations and large‐scale transport simulations, this study demonstrates that such control is enabled in a newly designed quinone‐NPG (q‐NPG) thanks to its GNRs inter‐connections based on electroactive para‐benzoquinone units. As a result, the spatial distribution of injected currents in q‐NPG may be tuned, with sub‐nanometer precision, via the application of external electrostatic gates and electrochemical means. These results thus provide a fundamental strategy to design organic nanodevices with built‐in externally tunable electronics and spintronics, which is key for future applications such as bio‐chemical nanosensing and carbon nanoelectronics.

Unveiling the Multiradical Character of the Biphenylene Network and Its Anisotropic Charge Transport

“…Specifically, the six-membered rings are connected via single C–C bonds along the x -direction, whereas they are connected via two C–C bonds along the y -direction (see Figure a) which form the CBD-like ring. It has already been shown, via large-scale transport simulations, that structurally anisotropic carbon 2D materials lead to anisotropic electronic transport, such as in the case of nanoporous graphenes − or in the so-called grazynes. , A recent study of BPN has also predicted that phonons (i.e., thermal energy) are transported differently along the two in-plane directions . However, till date, the electronic transport characteristics of this novel 2D material remain to be investigated.…”

“…50,51,71 The application of electrostatic gates was simulated via a fixed plane of charge parallel to the BPN layer and placed 3.5 Å below it, as previously carried out in other studies. 52,72 This was carried out with the PBE functional, as implemented in the Siesta code. These calculations were carried out using a 2 × 2 unit cell and applying gates, ranging from +1 electron per cell (n-doping) to −1 electron per cell (p-doping), as shown in Figure S5 in Supporting Information.…”

Molecular Bridge Engineering for Tuning Quantum Electronic Transport and Anisotropy in Nanoporous Graphene

“…24 Quantum simulations on electron propagation in different proposed NPG nanoarchitectures indicate that the interribbon transmission can be switched on/off by the chemical modification of the coupling bridges. 25,26 In this work, we present the synthesis of a new nanoporous graphene (NPG) structure where such chemical knobs are introduced and where the interribbon coupling strength can be additionally modulated by a continuous conformational transformation of the molecular bridges. The multiple bonding configurations of the bisphenylene bridges that bind the nanoribbons in this NPG can efficiently switch the interribbon electron flow off by incorporating meta bonds.…”

Electric‐Field‐Tunable Bandgaps in the Inverse‐Designed Nanoporous Graphene/Graphene Heterobilayers

“…The past decade has seen rapid development in a bottom-up synthesis of atomically precise nanostructures, such as graphene nanoribbons (GNRs) with precise widths and edge shapes [1][2][3][4][5][6][7][8][9] and nanoporous graphene (NPG) with periodic nanopores. [10][11][12][13][14] The progress in such nanomaterial synthesis has enabled band engineering of graphitic nanostructures. 1D topological phases, for example, were recently realized in GNRs via the rational design and bottom-up synthesis of GNR superlattices.…”