Large-Scale Sublattice Asymmetry in Pure and Boron-Doped Graphene

Abstract

The implementation of future graphene-based electronics is essentially restricted by the absence of a band gap in the electronic structure of graphene. Options of how to create a band gap in a reproducible and processing compatible manner are very limited at the moment. A promising approach for the graphene band gap engineering is to introduce a large-scale sublattice asymmetry. Using photoelectron diffraction and spectroscopy we have demonstrated a selective incorporation of boron impurities into only one of the two graphene sublattices. We have shown that in the well-oriented graphene on the Co(0001) surface the carbon atoms occupy two nonequivalent positions with respect to the Co lattice, namely top and hollow sites. Boron impurities embedded into the graphene lattice preferably occupy the hollow sites due to a site-specific interaction with the Co pattern. Our theoretical calculations predict that such boron-doped graphene possesses a band gap that can be precisely controlled by the dopant concentration. B-graphene with doping asymmetry is, thus, a novel material, which is worth considering as a good candidate for electronic applications.

FePc Adsorption on the Moiré Superstructure of Graphene Intercalated with a Cobalt Layer

“…11 More recently, by photoelectron diffraction measurements performed on the same system, a separation value between the two main components of about 270 meV has been estimated. 25 At the DFT-LDA level, the optimized Co-Gr distance for this configuration is found to be 2.05Å, in good agreement with existing literature. 17,24 The C1s core-level shifts computed for these two C sites differ by about 180 meV.…”

“…The splitting between these two peaks had been previously computed within the initial states approximation in Ref. 25 (ISA), where a larger value of 350 meV was found. This discrepancy can be explained by the fact that ISA neglects relaxation effects of the valence and core electrons upon ionization of the core.…”

Exclusive sub-lattices for extended and localized states in graphene ribbons: their role in Klein tunneling, disorder and magnetic field effects

“…In general, this occurs if the impurities are randomly located in sites corresponding to the sub-lattice LS and therefore they do not contribute to the electronic transport. Thus, the recent reported phenomenon [23][24][25][26] in which doping occurs asymmetrically between the two sublattices (A and B) is a current interesting topic related to our work.…”

Physi-Sorption of H2 on Pure and Boron–Doped Graphene Monolayers: A Dispersion–Corrected DFT Study

“…They reported the chemical structure of the doped sheets changed from a disordered (less π-conjugated) state with a B-puckered configuration at 600 to 800 • C to an ordered (highly π-conjugated) state with a planar configuration at 1500 • C. The planar graphitic layers were reported to accommodate <3% of B content, while the amorphous, BC x -like materials exhibited much higher surface areas (500 to 800 m 2 /g) and 12% B content with electron-deficient B moieties, resulting in enhanced H 2 binding energies (-12 to −20 kJ/mol at higher coverage). In a recent joint experimental and computational effort [33], a site-specific selective incorporation of B into the graphene sublattices was demonstrated to form a tunable band gap controlled by the dopant concentration. Shcherban et al [34] reported a nanocasting approach to prepare B-doped CMK-3 using SBA-15 as an exo-template.…”