Band Gap Engineering via Edge-Functionalization of Graphene Nanoribbons

Philipp Wagner (1) , Christopher Ewels (1) , Jean-Joseph Adjizian (1) , Laurence Magaud (2) , Pascal Pochet (3) , Stephan Roche (4, 5) , Alejandro Lopez-Bezanilla (6) , Viktoria V. Ivanovskaya (7) , Abu Yaya (8) , Mark Rayson (9) , Patrick Briddon (1, 10) , Bernard Humbert (1)

1 IMN - Institut des Matériaux Jean Rouxel
2 NEEL - Quan2m - Interactions modulables dans des états quantiques 2D
3 LSIM - Laboratory of Atomistic Simulation
4 ICN2 - Institut Català de Nanociència i Nanotecnologia
5 ICREA - Institució Catalana de Recerca i Estudis Avançats = Catalan Institution for Research and Advanced Studies
6 ANL - Argonne National Laboratory [Lemont]
7 Laboratoire Albert Fert (ex-UMPhy Unité mixte de physique CNRS/Thales)
8 Department of Materials Science and Engineering
9 Department of Chemistry
10 School of Electrical, Electronic and Computer Engineering

Density functional calculations are used to perform a systematic study of the effect of edge-functionalization on the structure and electronic properties of graphene nanoribbons (GNRs). −H, −F, −Cl, −Br, −S, −SH, and −OH edge-functionalization of armchair, zigzag, and reconstructed Klein-type GNRs was considered. The most energetically favorable edge structure varies depending on the choice of functional group. It is shown, for the first time, that reconstructed Klein-type GNRs are important stable configurations for several edge-functional groups. Band gaps using three different exchange-correlation functionals are calculated. The band gap for armchair GNRs can be tuned over a range of 1.2 eV by varying the edge-functional groups. In contrast, the band gaps of zigzag and reconstructed Klein edge GNRs are largely insensitive to the choice of edge-functional group, and ribbon width is instead the defining factor. Alternatively, the armchair GNR band gap can be controlled by varying the number of functional groups per opposing edge, altering the GNR "effective" width. Edge-functionalization design is an appropriate mechanism to tune the band gap of armchair GNRs.

Domaines: Science des matériaux [cond-mat.mtrl-sci]

Philipp Wagner, Christopher Ewels, Jean-Joseph Adjizian, Laurence Magaud, Pascal Pochet, et al.. Band Gap Engineering via Edge-Functionalization of Graphene Nanoribbons. Journal of Physical Chemistry C, 2013, 117 (50), pp.26790. ⟨10.1021/jp408695c⟩. ⟨hal-00950629⟩