| AVS 61st International Symposium & Exhibition | |
| 2D Materials Focus Topic | Wednesday Sessions |
| Session 2D+AS+EM+MI+MN+NS+TF-WeA |
| Session: | Properties of 2D Materials |
| Presenter: | Josue Morales-Cifuentes, University of Maryland, College Park |
| Authors: | J.R. Morales-Cifuentes, University of Maryland, College Park T.L. Einstein, University of Maryland, College Park Y. Wang, University of Maryland, College Park J. Reutt-Robey, University of Maryland, College Park |
| Correspondent: | Click to Email |
An effective potential mechanism for breaking the inherent sublattice symmetry of graphene has been studied using DFT calculations on hexagonal boron nitride.1 Electrical detection of CF3Cl phase transitions on graphene shows the existence of a commensurate ordered phase in which this can be tested.2 We study the electronic properties of similar phases varying coverage and orientation of CF3Cl with respect of the graphene substrate using VASP ver 5.3.3, with ab initio van der Waals density functionals (vdW-DF1, vdW-DF2).3 4 Consistent with a physisorbed phase, binding energies are calculated to be on the order of 280meV, and insensitive to coverage and orientation of the CF3Cl molecules. Charge transfer was calculated to be sensitive with coverage, but not orientation, which is qualitatively consistent with experiment. For low coverages, sub-lattice symmetry breaking effects are responsible for gap openings in the order of 4meV, whereas for large coverages it is the formation of ordered overlayers that opens gaps of 15meV. Furthermore, in bilayer graphene at low coverage we estimate an enhanced gap of 20meV.
[1] Gianluca Giovannetti et al. , PRB 76, 073103(2007)
[2] Yilin Wang et al. , APL 103, 201606 (2013)
[3] Jiri Klimes et al. , PRB 83, 195131 (2011)
[4] Kyuho Lee et al. , PRB 82, 081101(R) (2010)