@article{mao_kong_gong_xu_jayasekera_cho_kim_2013, title={First-principles calculation of thermal transport in metal/graphene systems}, volume={87}, ISSN={1098-0121 1550-235X}, url={http://dx.doi.org/10.1103/PhysRevB.87.165410}, DOI={10.1103/physrevb.87.165410}, abstractNote={Thermal properties in the metal/graphene (Gr) systems are analyzed by using an atomistic phonon transport model based on Landauer formalism and first-principles calculations. The specific structures under investigation include chemisorbed Ni(111)/Gr, physisorbed Cu(111)/Gr and Au(111)/Gr, as well as Pd(111)/Gr with intermediate characteristics. Calculated results illustrate a strong dependence of thermal transfer on the details of interfacial microstructures. In particular, it is shown that the chemisorbed case provides a generally smaller interfacial thermal resistance than the physisorbed one due to the stronger bonding. However, our calculation also indicates that the weakly chemisorbed interface of Pd/Gr may be an exception, with the largest thermal resistance among the considered. Further examination of the electrostatic potential and interatomic force constants reveals that the mixed bonding force between the Pd and C atoms results in incomplete hybridization of Pd and graphene orbital states at the junction, leading effectively to two phonon interfaces and a larger than expected thermal resistance. Comparison with available experimental data shows good agreement. The result clearly suggests the feasibility of phonon engineering for thermal property optimization at the interface.}, number={16}, journal={Physical Review B}, publisher={American Physical Society (APS)}, author={Mao, R. and Kong, B. D. and Gong, C. and Xu, S. and Jayasekera, T. and Cho, K. and Kim, K. W.}, year={2013}, month={Apr} }
 @article{jayasekera_xu_kim_nardelli_2011, title={Electronic properties of the graphene/6H-SiC(0001¯) interface: A first-principles study}, volume={84}, ISSN={1098-0121 1550-235X}, url={http://dx.doi.org/10.1103/PhysRevB.84.035442}, DOI={10.1103/physrevb.84.035442}, abstractNote={Using calculations from first principles, we show how the structural and electronic properties of epitaxial graphene on 6H-SiC(0001) are determined by the geometry and the chemical functionalization of the interface region. We also demonstrate that these properties can be correctly captured only if a proper treatment of the van der Waals interactions is included in the theoretical description based on density functional theory. Our results reproduce the experimentally observed n-type doping of monolayer epitaxial graphene and prove the possibility of opening a sizable (150 meV) energy gap in the bilayer case under special growth conditions. Depending on the details of the bonding at the interface, we are able to interpret recent experimental observations and provide a clear insight into the mechanisms of charge transfer and interface stability.}, number={3}, journal={Physical Review B}, publisher={American Physical Society (APS)}, author={Jayasekera, Thushari and Xu, Shu and Kim, K. W. and Nardelli, M. Buongiorno}, year={2011}, month={Jul} }