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We study theoretically the carrier transport and the plasmonic phenomena in the gated structures with dense lateral carbon nanotube (CNT) networks (CNT “felt”) placed between the highly-conducting slot line electrodes. The CNT networks under consideration consist of a mixture of semiconducting and metallic CNTs. We find the dispersion relations for the two-dimensional plasmons, associated with the collective self-consisted motion of electrons in the individual CNTs, propagating along the electrodes as functions of the net electron density (gate voltage), relative fraction of the semiconducting and metallic CNTs, and the spacing between the electrodes. In a wide range of parameters, the characteristic plasmonic frequencies can fall in the terahertz (THz) range. The structures with lateral CNT networks can used in different THz devices.

In this paper, the optical scattering from cylindrical plasmonic nanoparticles with a core–shell structure, while the core is dielectric coated by a metallic shell such as gold, is investigated by using an analytical solution in the framework of Mie theory. A closed-form (CF) formalism that determines the optical properties of cylindrical nanoparticles based on the series expansions of Bessel functions for the Mie scattering coefficients is introduced and presented. By using this formulation, we will show the optical response and the surface plasmon resonance of hybrid metal-based nanoparticles with cylindrical shape is dependent on the radius of nanoparticle, the refractive index of core and physical environment of nanoparticle. Also, the influence of interband transitions on the optical scattering by plasmonic nanoparticles is discussed and interpreted using the Drude–Lorentz model because the optical properties of metals arise from both the optical excitation of interband transitions and the free electron response.

In this work, we report an amplified strong coupling phenomenon in a hybridized nanowire. The hybridized nanowire structure is composed of CH₃NH₃PbBr₃ perovskite nanowire coated by SiO₂ film and silver film. Due to the existence of silver film, Rabi splitting in hybrid structure can reach 303.2 meV, while the Rabi splitting in a pure perovskite nanowire is only 236.4 meV. Also, thicknesses of SiO₂ film and Ag film can control the Rabi splitting of hybridized structure: (i) the thicker the Ag film, the greater the Rabi splitting; (ii) the thinner the SiO₂ film, the greater the Rabi splitting. Finally, index of SiO₂ film shows a linear relation with Rabi splitting.

Recently, defective metal oxides have attracted vast attention for their potential applications arising from their increased free carrier concentration. In this study, monoclinic MoO₃ films have been grown on quartz glass substrates by hydrogen flame synthesis, as a fast and mass-productive method. The MoO₃ films then were reduced to defective MoO${}_{3-x}$ by a flame-reduction treatment using a butane torch. After reduction, the localized surface plasmon resonance (LSPR) absorption band appeared in the NIR region that was employed for NIR-shielding applications. Films were reduced at a nozzle-to-sample distance ranging from 1 to 4cm, and the optical properties of these films were investigated at an optimum distance (2cm) as a function of reducing duration time ranging from 1 to 20s. The increase in the inner and outer temperatures were measured in the heat-shielding experiment and the optimum reducing condition was determined. Overall, we have developed a fast, mass-productive and cost-effective method for fabrication of heat-shielding devices based on LSPR effect.

Bimetallic nanostructure of noble metals is an alternative material that can provide the tenability of plasmonic performance. In this study, the plasmonic silver–titanium nanoisland (Ag–Ti NI) films deposited on a silicon wafer and glass slide substrates were prepared by magnetron co-sputtering of high-purity Ag target (99.99%) operated at 100 W-DC source, and Ti target (99.99%) operated at 50–250 W-DC pulsed source. The surface morphologies of the prepared films revealed a noncontinuous island Ag–Ti according to the formation of thin film growth based on the Volmer–Weber model. An increase in the sputtering power of the Ti target caused an evident increase in the Ag–Ti NIs diameter. The localized surface plasmon resonance (LSPR) was evaluated by UV–Vis–NIR spectrophotometry. The LSPR peak shift disappears with an increase of the sputtering power of the Ti target.In addition, the results confirmed that the surface-enhanced Raman scattering (SERS) activity of the bimetallic Ag–Ti NIs significantly improved in performance and stability, which is promising for the application in analytical chemistry.

Surface-enhanced Raman scattering (SERS) has attracted much attention as an important technique for studying and monitoring the behavior of molecules. Coherent control by shaping femtosecond pulses is an efficient method for controlling molecular vibration state, rotation state, ionization state, and other molecule dynamics. In this paper, we propose a theoretical scheme of selective excitation of SERS from a single porphycene molecule with two Raman peaks at 327cm${}^{-1}$ and 367cm${}^{-1}$ placed in the gap between silver dimer nanospheres. Based on the theory of quantum coherent control, selective excitation of the peak at 327cm${}^{-1}$ and depression of another at 367cm${}^{-1}$ are demonstrated by properly shaping femtosecond laser pulses with central frequency of 12500cm${}^{-1}$ and a full width at half maximum (FWHM) of 300cm${}^{-1}$. Ultrafast dynamics of the response of dimer nanospheres to the shaped pump and Stokes pulses are simulated by finite difference time domain (FDTD) method followed by Fourier transform. The enhanced and selected single molecule SERS is realized simultaneously. The SERS probability is enhanced by more than six orders in magnitude compared with the case in air environment, and the FWHMs of the enhanced and the depressed Raman peaks are both larger than 17cm${}^{-1}$ despite the narrow gap of only 40cm${}^{-1}$ between the two Raman peaks.

A novel plasmonic waveguide structure consisting of a rectangular resonator side coupled with a split ring resonator (SRR) and a metal–insulator–metal (MIM) waveguide with metal baffle was proposed. The transmission characteristics of the present structure were simulated by a finite-difference time-domain (FDTD) method. The results show that the structure can realize three typical plasmonically-induced reflection (PIR) windows. Meantime, the PIR window can be tuned vertically and horizontally, respectively, and multiple PIR windows with different wavelength intervals can also be obtained by changing the split position. In addition, the sensitivity of the proposed structure can reach up to 1,075nm/RIU. Furthermore, a rectangular resonator was added to the other side of the plasmonic waveguide structure for realizing the dual-channel PIR window. Another SRR was added to form a symmetrical structure, which further improved the sensitivity and transmittance. Undoubtedly, the proposed structure will have potential applications in sensor and optical switches.

Plasmonic phenomena in nanostructured surfaces are modeled by considering isotropic point-like nanoparticles whose responses to an incident surface plasmon polariton (SPP) field are phenomenologically related to their effective polarizabilities. Numerical simulations of different SPP elastic (in-plane) scattering orders and the operation of simple plasmonic devices are presented. Futhermore, nonlinear microscopy with a tightly focused laser beam scanning over a sample surface was modeled by using of analytic representations of the Green dyadic in the near- and far-field regions, with the latter being approximated by the part describing the scattering via excitation of SPPs. In general, the stability with respect to geometrical parameters and dispersion were the main features investigated in the presented plasmonic phenomena.

Simulation methods are vital to the development of next-generation solar cells such as plasmonic, organic, nanophotonic, and semiconductor nanostructure solar cells. Simulations are predictive of material properties such that they may be used to rapidly screen new materials and understand the physical mechanisms of enhanced performance. They can be used to guide experiments or to help understand results obtained in experiments. In this paper, we review simulation methods for modeling the classical optical and electronic transport properties of nanostructured solar cells. We discuss different techniques for light trapping with an emphasis on silicon nanostructures and silicon thin films integrated with nanophotonics and plasmonics.

We study theoretically the carrier transport and the plasmonic phenomena in the gated structures with dense lateral carbon nanotube (CNT) networks (CNT “felt”) placed between the highly-conducting slot line electrodes. The CNT networks under consideration consist of a mixture of semiconducting and metallic CNTs. We find the dispersion relations for the two-dimensional plasmons, associated with the collective self-consisted motion of electrons in the individual CNTs, propagating along the electrodes as functions of the net electron density (gate voltage), relative fraction of the semiconducting and metallic CNTs, and the spacing between the electrodes. In a wide range of parameters, the characteristic plasmonic frequencies can fall in the terahertz (THz) range. The structures with lateral CNT networks can used in different THz devices.