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Back Cover (Phys. Status Solidi A 9/2010)
Author(s) -
Pinto H.,
Jones R.,
Goss J. P.,
Briddon P. R.
Publication year - 2010
Publication title -
physica status solidi (a)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.532
H-Index - 104
eISSN - 1862-6319
pISSN - 1862-6300
DOI - 10.1002/pssa.201090020
Subject(s) - graphene , bilayer graphene , doping , graphene nanoribbons , materials science , nanotechnology , chemical physics , condensed matter physics , chemistry , optoelectronics , physics
Different mechanisms of doping graphene are studied by Pinto et al. ( pp. 2131–2136 ) using density functional theory. A first type can be called electronic doping and occurs when there is a direct exchange of electrons between graphene and an adsorbate. Examples are electronegative molecules like F4‐TCNQ and electropositive metals like K which lead to p‐ and n‐type doped graphene, respectively. The cover image shows the wavefunctions of the electronic levels of a K atom on top of graphene at the Brillouin zone point marked as A and is clearly localised on the K atom while the wavefunction of the level marked as B is delocalised over the graphene layer. Such doping occurs promptly, leads to a reduction in the carrier mobility, and there should be no hysteresis effects. Furthermore, a novel doping mechanism is exhibited by Au which dopes bilayer graphene but is less effective for a single layer. A third mechanism of doping graphene, electrochemical doping, occurs by redox reactions on the graphene surface. It can result in p‐doping by humid atmosphere or n‐doping by NH 3 and toluene. This mechanism of doping requires appreciable time to occur and can lead to an increase in the carrier mobility and hysteresis effects.