We design and fabricate two terahertz (THz) filters based on frequency selective surfaces' structures (FSSs) on single crystal sapphire substrate, which show high and low transmissivities to THz electromagnetic waves, respectively. The difference of THz transmissivity between two filters reaches up to 72% at the resonance frequency of 1.35 THz. The THz filtering effect is due to the resonant coupling between THz wave and periodic metallic elements and the filter operating frequency can be tuned systematically by the geometry of FSSs. The good agreement between experiments and finite difference time domain simulation indicates that a high-speed THz switch could be realized for THz active devices based on the FSSs.

No abstract

Highly ordered mesoporous silica thin films (MSTFs) were spin-coated on Si wafers by self-assemble of water-soluble nanocrystal micelles with soluble silica. The gold nanoparticles (GNPs) were assembled within the silica matrix. Based on this nanocomposite, nanoscale electrodes were fabricated to form single electron devices. Two main transport behaviors of resemblant Coulomb blockage were demonstrated in the current-voltage measurements. The Coulomb island size calculated from the current-voltage data was close to the real size of the GNPs. The random loading positions of GNPs in the MSTF, which lead to uncertain tunneling resistances, might be response for the conductive differences.