We use Au@SiO2 nanoparticles（NPs） to systematically and comprehensively study the relationship between nanostructure and activity for surface-enhanced Raman scattering. Calculation simulation using the finite differ...We use Au@SiO2 nanoparticles（NPs） to systematically and comprehensively study the relationship between nanostructure and activity for surface-enhanced Raman scattering. Calculation simulation using the finite different time domain method verifies the experiment results and further reveals that the particle size and the distance between the NPs play vital roles in the surface-enhanced Raman scattering（SERS）. Furthermore, in order to better simulate the real experiment, a Au@SiO2 nanosphere dimer is placed on the silicon substrate and Au substrate, separately. The simulation results show that the large EM field coupling is due to the ＂hot spots＂ transferred from the NP–NP gaps to NP–surface of metal gaps,meanwhile, more ＂hot spots＂ occur. We also find that the signal intensity strongly depends on the position of the probe molecule. This work provides a better understanding of EM field enhancement.展开更多
New transmission line equations are deduced applying Maxwell's equations in this paper. The conditions of the classical transmission line equations have been discussed, which is important to solve the EM problems ...New transmission line equations are deduced applying Maxwell's equations in this paper. The conditions of the classical transmission line equations have been discussed, which is important to solve the EM problems in high frequency case.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.61177004)
文摘We use Au@SiO2 nanoparticles（NPs） to systematically and comprehensively study the relationship between nanostructure and activity for surface-enhanced Raman scattering. Calculation simulation using the finite different time domain method verifies the experiment results and further reveals that the particle size and the distance between the NPs play vital roles in the surface-enhanced Raman scattering（SERS）. Furthermore, in order to better simulate the real experiment, a Au@SiO2 nanosphere dimer is placed on the silicon substrate and Au substrate, separately. The simulation results show that the large EM field coupling is due to the ＂hot spots＂ transferred from the NP–NP gaps to NP–surface of metal gaps,meanwhile, more ＂hot spots＂ occur. We also find that the signal intensity strongly depends on the position of the probe molecule. This work provides a better understanding of EM field enhancement.
文摘New transmission line equations are deduced applying Maxwell's equations in this paper. The conditions of the classical transmission line equations have been discussed, which is important to solve the EM problems in high frequency case.
