title: Structure and functionality of bromine doped graphite.
abstract: First-principles calculations are used to study the enhanced in-plane conductivity observed experimentally in Br-doped graphite, and to study the effect of external stress on the structure and functionality of such systems. The model used in the numerical calculations is that of stage two doped graphite. The band structure near the Fermi surface of the doped systems with different bromine concentrations is compared to that of pure graphite, and the charge transfer between carbon and bromine atoms is analyzed to understand the conductivity change along different high symmetry directions. Our calculations show that, for large interlayer separation between doped graphite layers, bromine is stable in the molecular form (Br2). However, with increased compression (decreased layer-layer separation) Br2 molecules tend to dissociate. While in both forms, bromine is an electron acceptor. The charge exchange between the graphite layers and Br atoms is higher than that with Br2 molecules. Electron transfer to the Br atoms increases the number of hole carriers in the graphite sheets, resulting in an increase of conductivity.
authors: Department of Physics and Quantum Theory Project, University of Florida, Gainesville, Florida 32611, USA. rashid@phys.ufl.edu
authors: Rashid
authors: R
authors: Hamdan
authors: A F
authors: AF
authors: Kemper
authors: Chao
authors: C
authors: Cao
authors: H P
authors: HP
authors: Cheng
mesh_terms: D001966:Bromine / Q000737:chemistry*; D006108:Graphite / Q000737:chemistry*; D015394:Molecular Structure; D011789:Quantum Theory
chemical_list: D006108:Graphite; D001966:Bromine