Nonlinear features of Fano resonance: a QM/EM study.

The nonlinear Fano effects on the absorption of hybrid systems composed of a silver nanosphere and an indoline dye molecule have been systematically investigated by the hybrid approach, which combines the quantum mechanics method (QM) with the computational electromagnetic method (EM). The absorption spectra of the dye molecule in the proximity of an Ag nanoparticle have been calculated by changing the incident field intensity, the phenomenological dephasing of molecular excitation, and the enhancement ratio of the near field. The contribution of molecular nonlinear response properties and the quantum interferences of the incident and scattered fields and of resonant plasmon-molecular excitations to the spectra has been identified.

Effect of electrodes on geometric and transport properties of the graphene-based nanomolecular devices.

Graphene-based nanomolecular devices are formed by connecting one of the prototype molecular materials of graphene nanoribbons to two Au electrodes. The geometric structure and electronic properties are calculated by using density functional theory. Basing on the optimized structure and the electronic distributions, we obtain the transport properties of the devices by using the Green's functional method.

The finite-size effect on the transport properties in edge-modified graphene nanoribbon-based molecular devices.

The size-dependence on the electronic and transport properties of the molecular devices of the edge-modified graphene nanoribbon (GNR) slices is investigated using density-functional theory and Green's function theory. Two edge-modifying functional group pairs are considered. Energy gap is found in all the GNR slices.

Surfactant effect of Au on Ga adsorption on GaAs(0001) surface.

Basing on the density-functional theory, we have investigated the atomistic and electronic structures of Ga adsorption on GaAs(0001) surface with pre-absorbed Au monolayer for the understanding of the surfactant effect of Au on the growth of GaAs nanowires. The results show that the deposited Au layer enhances significantly the stability of the Ga adatom on substrate compared to the direct adsorption of Ga on GaAs(0001) surface. The reason is that more electrons of the Ga 6p levels are transferred toward surface bands of substrate because of mediation of the Au layer.

Transport properties of graphene nanoribbon-based molecular devices.

The electronic and transport properties of an edge-modified prototype graphene nanoribbon (GNR) slice are investigated using density functional theory and Green's function theory. Two decorating functional group pairs are considered, such as hydrogen-hydrogen and NH(2)-NO(2) with NO(2) and NH(2) serving as a donor and an acceptor, respectively. The molecular junctions consist of carbon-based GNR slices sandwiched between Au electrodes.