This article is a comprehensive review of the subject of near-field nano imaging and spectroscopy by surface plasmon polaritons induced on a metallized probe. The emphasis of the review is on fundamental aspects of plasmon enhancement and near-field spectroscopy, which are categorized as optical antenna structures, polarization properties in near-field, resonance frequency of surface plasmons, etc. Most recent studies that contribute to the understanding and interpretation of these phenomena are highlighted. Applications of near-field optics as newly established analytical tools for biology, materials sciences and plasmonic superlenses are included in the article.

In this paper, we present a model proposition of photo-SET (single electron photo-detector) aiming at detecting one by one electrons. In the first part of this work, we present the two blocs of the proposed photo-SET (reading and detection blocs). The device structure presented is consisting of two SETs capacitively coupled. In this model, the first SET (SET1) is supposed to read the charge whereas the detection bloc is represented by the second SET (SET2). In the second part, we investigate the effects of photoexcitation on Id-Vg curves and we present results obtained on the output photo-SET characteristics after variation of power illumination and response time.

In this study, new possibilities for higher efficiency poly-Si thin film solar cells are investigated using MEDICITM device simulator. The poly-Si p+-n-n+ thin film solar cell with a thin a-Si p+ layer is found to have higher efficiency than the homojunction p+-n-n+ cell. Further improvement in efficiency of the heterojunction p+-n-n+ cell is achieved by introducing a thin μc-Si layer at the interface of a-Si emitter and poly-Si absorber layers. The μc-Si layer at the interface is found to reduce the recombination losses at the interface and improved the fill factor and efficiency of the cell. The photovoltaic parameters of the cell and the absorber layer thickness for optimum efficiency are highly influenced by grain size and passivation at the grain boundary.

Electrical measurements of Se$_{98-X}$Zn2InX (X = 0, 2, 4, 6 and 10) chalcogenide glasses have been carried out at room temperature. I-V characteristic of the present glasses were recorded upto 200 V. A drastic changes in I-V characteristic have been observed between 180 to 200 V for 4, 6, 10 at% of indium. The composition dependence of electrical conductivity is also discussed.

Current voltage and capacitance-voltage characteristics for SnPc thin film with ~105 nm thickness; deposited on p-GaAs single crystals have been investigated. The dark current voltage-characteristics of the prepared junction have been investigated in a temperature range from ~303 to 393 K. The obtained results showed rectification behaviour. At low forward and reverse bias, the current was found to be limited by the thermoionic emission, while at high forward voltage, space charge limited current dominated by a single trap level of 0.22 eV. The analysis of the dark capacitance voltage characteristics indicated that the carrier concentration is 1.4×1014 cm-3 with a built in voltage ~0.55 eV.

The current-voltage (I-V) and capacitance-voltage (C-V) characteristics of metal-organic compound conductive polymer-semiconductor Al/P2ClAn(C2H5COOH)/p-Si structures were measured in the temperature range 80–340 K. P2ClAn: the poly(2-chloroaniline). The P2ClAn emeraldine salt was synthesized chemically by using propionic (C2H5COOH) acid. The analysis of I-V characteristics based on the thermoionic emission (TE) mechanism has revealed a decrease of zero-bias barrier height and a increase of the ideality factor at lower temperatures. Temperature dependence of the barrier height (BH) has shown a disagreement with those calculated from C-V characteristics. This behaviour is attributed to Schottky barrier inhomogeneities at interface. The temperature coefficient of BH has been found to be -2.9×10-4 eV/K for Al/P2ClAn(C2H5COOH)/p-Si. ln(I0/$T^{2})$ versus 1/T plot gives activation energy and Richardson constant $A^{\ast}$ as 0.12 eV and 3.82×10-9 A/K2 cm2, respectively.

The structural investigations of model organic systems like pentacene on silicon oxide in the monolayer regime is very important for the basic understanding of initial nucleation process together with the electronic performance of transistor devices. A method for the evaluation of the island formation and layer closing of the first monolayer is introduced. The method is based on specular X-ray reflectivity and diffuse scattering and reveal integral information on the coverage together with the size and separation of pentacene islands. The results are in good agreement with AFM investigation that encourages the use of this type of investigation in in-situ experiments.

The work we present in this article is an investigation of the optimal dielectric behaviour of a ternary composite based on a mixture of epoxy resin, titanates and oxides. Titanates are known by their capacity to provide high dielectric constant values that make their use very important in system of telecommunication, transmission microwaves, and in integrated circuit technology. A comparative study is established on two types of oxides added to titanates of either calcium, barium, or magnesium following different proportions. The protocol used to characterise different mixtures is the Time Domain Reflectometry (TDR). The acquired results show a good concordance between the experimental values of the ternary mixture dielectric constant and the theoretical models deduced from the Lichtenecker modified law. The copper oxide (CuO) is revealed to be more influential than the magnesium oxide (MgO) on the added titanate because of an insignificant dielectric behaviour that the latter presents. On the other hand, the linear behaviour of $\varepsilon_{s}$ appeared with a CuO concentration round about 15% in a RE.BT.CuO mixture. For a fixed barium titanate fraction (27%) this linear evolution is located between the upper and the lower limits derivative from direct and inverse Wiener laws.

This paper reports the examination of the evolution of polyaniline-organic solvent interactions in the temperature range of 294–353 K. For this purpose, rheological and dielectric investigations have been undertaken for dispersions of plast-doped polyaniline in two different solvents (dichloroacetic acid and formic acid/dichloroacetic acid mixture). Dielectric permittivity has been investigated using the open ended coaxial line method in the frequency range of [100 MHz, 10 GHz]. Dielectric loss spectra of both dispersions showed a relaxation peak which was well fitted by Havriliak-Negami function. The relaxation was attributed to a Maxwell Wagner Sillars relaxation within polyaniline clusters. The difference found between relaxation parameters of the pure solvent and polyaniline dispersions was attributed to the solvent/polyaniline interactions. The relaxation time relative to the PANI/DCAA dispersion followed an Arrhenius law. While a Vogel-Fulcher-Tammann law was found for the relaxation time of PANI/DCAA-FA dispersion. Above a certain temperature, 318 K for PANI/DCAA and 313 K for PANI/DCAA-FA, the rheological parameters of the dispersions changed, thus indicating a morphological change of polyaniline in the dispersion. In the same range of temperature, α and β relaxation parameters undergo significant changes. Those changes in dielectric and rheological parameters seem to be related to a structural change occurring in the polyaniline organic dispersion systems while increasing temperature. An interesting correlation between permittivity and viscosity was obtained.

Pulsed laser deposition method was used to prepare Bi2Te3 thermoelectric thin films on a soda lime glass substrate at room temperature. Surface morphology of Bi2Te3 thin films was studied by AFM (atomic force microscopy) images. The influence of thermal annealing in vacuum condition on microstructure and surface morphology of films was investigated in wide range of temperature. The results demonstrate that annealing induces a transition from amorphous to polycrystalline structures and increases electrical conductivity. X-ray diffraction analysis proves that the film annealed at 300 °C for 120 min appears in large grain size polycrystalline structure but film annealed at 400 °C in the same condition has a preformed crystal growth texture in (006) direction.

First principles density functional calculations are used to study the uniaxial strain effects on the energy band structures of single- and multi-walled boron nitride nanotubes. Simulation results show that tensile strain induces a slight decrease in band gaps, while small and large compressive strains induce slight increases and decreases of band gaps, respectively. The maximum change of the band gap is ~0.5 eV. The band structures of all the nanotubes are not sensitive to uniaxial strain, which means that the boron nitride nanotubes could be used in blue and UV light-emitting devices under large uniaxial strain.

Metallic Ag-nanoparticles have been synthesized by catalyst free chemical and photochemical reduction processes. During photochemical synthesis, the samples were illuminated independently by unpolarized and radially-polarized continuous laser beams (λ = 632.8 nm). The nanoparticles were characterized by bright-field transmission electron microscopy (TEM), linear absorption spectroscopy and fluorescence excitation/emission spectroscopy. Compared to other growth-conditions, sample prepared under radially polarized beam essentially displays well-separated, spherical nanoparticles with a narrow size distribution around average size of 6 nm. In addition, an outstanding enhancement in the fluorescence as large as 39% has been achieved along with observation of distinct localized surface plasmon states. Though the sample produced under unpolarized light could exhibit discrete plasmon states, better resolved states were observed in case of use of radially-polarized beam. It is expected that the radially polarized light could induce resonance energy transfer and hence could control growth conditions giving rise to absolutely unclustered Ag-nanoparticles. Detecting such localized surface plasmon states and understanding conditions of high quantum yield would be promising for single molecule fluorescence, superresolution microscopy and other nanoscopic applications.

The electric field responses of strongly nonlinear dielectric composites that consist of elliptical strongly nonlinear dielectric inclusions which are randomly oriented and embedded in different strongly nonlinear dielectric media in the dilute limit are investigated. By using the decoupling approximation, the effective nonlinear coefficients ($\chi_{e}$) are determined for varying the contrast between the nonlinear coefficients of inclusions and medium $(\chi_{i}/\chi_{m})$ with the aspect ratio, the ratio between semi major and semi minor axes, as parameters. The results show that increasing the aspect ratios within the range of 1 to 10 does not affect $\chi_{e}$ for low contrast $(\chi_{i}/\chi_{m}$ from 0.4 to 2.5). For high contrasts, the larger the aspect ratios, the greater the effects on $\chi_{e}$ are observed with enhancement and suppression of $\chi_{e}$ being observed at $\chi_{i}/\chi_{m}>1$ and $\chi_{i}/\chi_{m}<1$, respectively.

Based on the theory of coordinate transformation, the design of electromagnetic (EM) invisible cloak with a uniform thickness is proposed for arbitrarily polygonal-cylindrical regions. The designed equal-thickness cloak will force incoming EM waves to propagate around the inner polygonal region smoothly. Similar to the circular cloak, such EM waves will return to their original propagation directions without distorting the waves outside the cloak. Full-wave simulations are given to validate the design and analysis.

This paper presents simulation results for a microwave (2.45 GHz) plasma reactor, operated by an axial injection torch (AIT). The study gives a two-dimensional description of the AIT-reactor system, based on an electromagnetic model (that solves Maxwell's equations adopting a time-harmonic description, yielding the distribution of the electromagnetic fields and the average power absorbed by the plasma), and a hydrodynamic model (that solves the Navier-Stokes' equations for the flowing neutral gas, yielding the distribution of mass density, pressure, temperature, and velocities). Comparison between model results and experimental measurements reveal common variation trends, with changes in the reactor height, for the power reflected by the system, and yield a qualitative agreement for the axial profile of the gas rotational temperature. Model results, such as the power transmission coefficient and the gas temperature, are particularly dependent on the reactor dimensions, the electron density and temperature, and the gas input flow, which indicates that simulations can be used to provide general guidelines for device optimization.