Patterning nanoroads and quantum dots on fluorinated graphene

Abstract

Using ab initio methods we have investigated the fluorination of graphene and find that different stoichiometric phases can be formed without a nucleation barrier, with the complete "2D-Teflon" CF phase being thermodynamically most stable. The fluorinated graphene is an insulator and turns out to be a perfect matrix-host for patterning nanoroads and quantum dots of pristine graphene. The electronic and magnetic properties of the nanoroads can be tuned by varying the edge orientation and width. The energy gaps between the highest occupied and lowest unoccupied molecular orbitals (HOMO-LUMO) of quantum dots are size-dependent and show a confinement typical of Dirac fermions. Furthermore, we study the effect of different basic coverage of F on graphene (with stoichiometries CF and C 4 F) on the band gaps, and show the suitability of these materials to host quantum dots of graphene with unique electronic properties.

Layers and tubes of fluorographene C4F: Stability, structural and electronic properties from DFTB calculations

“…In agreement with the previous data [3,20,22], our results reveal that this isomer is semiconducting with the band gap (BG) about 3.8 eV, Table. The total and partial densities of states (DOSs, Figure 2) evidence that the top of the valence band is composed of hybridized orbitals of fluorine and carbon, whereas the bottom of the conduction band is mainly of C 2p type.…”

“…This method was earlier evaluated and applied for the simulations of various carbon-based bulk and nano-sized materials as well as for fluorocarbons -in reasonable agreement with the experimental data and high-level theoretical methods, see for example, [22,28]. The structures of the layers and nanotubes considered in this letter were fully relaxed under periodic boundary conditions using the conjugate gradient algorithm and 10 k-points for each direction of two-or one-dimensional reciprocal lattice.…”

“…In our simulations as the reference system we have used the single-sided fluorinated graphene C 4 F (further as isomer C 4 F-1) which has been synthesized [3,13] and studied theoretically [3,20,22]. Furthermore, we have constructed the atomic models of isomers C 4 F-2-C 4 F-4, see Figure 1, which describe the other possible variants of the adsorption of fluorine on graphene.…”

“…Lee et al [13] have prepared composite structures, where graphene nanoribbons are sandwiched between large areas of C 4 F. C 4 F with the single-sided fluorination type was characterized theoretically as a wide-band-gap semiconductor with LDA gap at about 3 eV [3,20,22]. It adopts the highest binding energy (per F atom) compared to other examined compositions CF 1Àx with single-sided type of fluorination [3].…”

Tuning the tunneling magnetoresistance by using fluorinated graphene in graphene based magnetic junctions

“…27,29 Band gap of fluorographene by theoretical calculations using DFT GGA have reported values around 3.1 eV. 28,[33][34][35][36] In this work, we reported band gap values of fluorinated graphene in CF configuration to be around ∼3.466 eV and for C 4 F configuration it is around 0.7 eV. Fluorinated graphene or fluorographene is an exceptional in-plane insulator, suggesting its use in spin based devices as a tunnel barrier.…”