ZnO thin films were firstly prepared on Si(111) substrates using radio frequency magnetron sputtering system. Then the samples were annealed at different temperature in oxygen ambient and their properties were investigated particularly as a function of annealing temperature. The microstructure, morphology and optical property of ZnO films were studied by XRD, AFM, FTIR and PL. The results show that the increase of annealing temperature leads to the improvement in the crystal quality.

Since the end of the last millenium, the microelectronics industry has been facing new issues as far as CMOS devices scaling is concerned. Linear scaling will be possible in the future if new materials are introduced in CMOS device structures or if new device architectures are implemented. Innovations in the electronics history have been possible because of the strong association between devices and materials research. The demand for low voltage, low power and high performance are the great challenges for the engineering of sub 50 nm gate length CMOS devices. Functional CMOS devices in the range of 5 nm channel length have been demonstrated. The alternative architectures allowing to increase devices drivability and reduce power consumption are reviewed. The issues in the field of gate stack, channel, substrate, as well as source and drain engineering are addressed. HiK gate dielectric and metal gate are among the most strategic options to consider for power consumption and low supply voltage management. By introducing new materials (Ge, diamond/graphite carbon, HiK, ...), Si based CMOS will be scaled beyond the ITRS as the future System-on-Chip Platform integrating also new disruptive devices. For example, the association of C-diamond with HiK, as a combination for new functionalized Buried Insulators, will bring new ways of improving short channel effects and suppress self-heating. Because of the low parasitics required to obtain high performance circuits, alternative devices will hardly compete against logic CMOS.

Rare-earth (RE) doped III-nitrides, prepared by in-situ doping during growth or by ion implantation and annealing, are promising materials for visible light emitting displays. In addition, they are extremely challenging theoretically, on account of the complexity of the sharp inter-4f optical transitions, which are allowed only through the mixing by non-centrosymmetric crystal fields of the inner 4f orbitals with higher-lying states of opposite parity. We review recent experimental and theoretical work on Er-, Eu- and Tm-doped III-nitride compounds and alloys which has been carried out with a view to establishing the lattice location of RE in these materials and the probable nanostructure of the centres which are responsible for their luminescence. The isolated site REIII is found to be both optically and electrically inactive, but in association with neighbouring intrinsic defects (most probably nitrogen vacancies) REIII can generate a small family of similar optically active sites. Such a family is held to be responsible for the site multiplicity that is a common feature of the spectroscopy of RE-doped III-nitrides.

LiNb$_{1-x}$TaxO3 thin films were successfully deposited on Pt(111)/Ti/SiO2/Si(100) substrates by spin coating with a diol-based sol-gel technology and rapid thermal annealing. The effects of various processing parameters, including Ta content (0$\leq x\leq1$) and heating temperature (500 ~ 800 °C), on the growth and properties of thin films were investigated. With the increase of Ta content, the grain size of film decreased slightly, and the maximum f factor (the degree of c-axis orientation) of the films were obtained in the composition of x = 0.2. As the composition of film varied from x = 0 to x = 1, the relative dielectric constant of film increased from 33 up to 62, and the dielectric loss factor (tanδ) also increased from 0.00374 to 0.00686, respectively. The coercive field, Ec, and remanent polarization, Pr, decreased but pyroelectric coefficient, γ, increased from 2.76 × 10−8 up to 4.51 × 10−8 C/cm2 K. The pyroelectric figures of merit, Fv and Fm, indicated that film with Ta content of 20 mol% and heating temperature of 700 °C exhibited the optimized pyroelectric characteristics and could be applied for high-performance pyroelectric thin-film detectors.

We have explored the effects of 120 MeV Si9+ ion beam irradiation on the electrical, structural and capacitance properties of HClO4 doped polyaniline conducting polymer electrodes. The swift heavy ion (SHI) irradiated conducting polymer films exhibited upto 70% increase in crystallinity and dc conductivity with improved surface morphology. The supercapacitors fabricated with ion irradiated polyaniline electrodes showed enhancement of electrochemical stability and slight decrease in internal resistance, which could be attributed to the removal or stabilization of the volatile surface groups and decrease in surface roughness upon ion irradiation. Fluence dependent small increase in coulombic efficiency is observed in the supercapacitors with SHI irradiated polymer electrodes because of the increase in dc conductivity of the polymer electrodes upon irradiation.

Trap parameters in poly(1-(3,4-difluorophenyl)-2-(4-pentylcyclohexylphenyl)acetylene) (PDPA-2F) based devices have been investigated by using the thermally stimulated current (TSC) technique. The device structure is ITO-PEDOT-(PDPA-2F)-M, where M stands for the cathode metal (Al, Ca/Al, and Au). The results reveal at least three TSC peaks in devices denoted as peaks A, B and C. Comparing trap parameters in ITO-PEDOT-(PDPA-2F)-Au hole-only device and ITO-PEDOT-(PDPA-2F)-Ca Al (Al) bipolar devices, we assigned A and B trap types to hole-like traps and C type traps to electron-like traps. The trap densities are in the range of 1015−1017 cm−3 and the trap levels are 0.12 eV (A type traps), 0.36 eV (B type traps), and 0.25 eV (C type traps).

The chalcopyrite CuAlS2 compound was grown from stoichiometric melt by horizontal Bridgman method. The obtained ingots were crushed finely and annealed at different temperatures from 800 °C to 1100 °C under a gas mixture of 5% N2/H2 atmosphere. X-ray diffraction and Raman spectroscopy were used to investigate the layer microstructures, as well as their lattice vibration spectra. The layers were characterized by scanning electron microscopy (SEM) and the compositional analyses were done by energy dispersive X-ray microanalysis (EDX). Raman measurements of the as made powder indicated seven prominent peaks at 205, 250, 290, 340, 369, 418 and 457 cm−1 with large intensity at 457 cm−1. The peaks at 205, 250, 340 and 457 cm−1 were ascribed to B2 modes while the peaks 369 and 418 cm−1 were ascribed to E modes. The peak at 290 cm−1 may be assigned to the A1 mode. After annealing, the Raman features become better and phonon mode at 290 cm−1 looks more distinct. The stoichiometric CuAlS2 compound was obtained when the sample was annealed at 900 °C.

In order to study the preferred crystal orientations of Mg-Zr-O composite protective layers in PDP, Mg-Zr-O composite protective layers were deposited by Electron-beam Evaporator using (MgO+ZrO2) powder mixture as evaporation source material. X-ray diffractometer (XRD) was used to determine preferred crystal orientations of Mg-Zr-O composite protective layers, surface morphologies of films were analyzed by FESEM and voltage characteristics were examined in a testing macroscopic discharge cell of AC-PDP. On the basis of experimental analysis, the influence of oxide addition and deposition conditions on preferred orientations of Mg-Zr-O composite protective layers were investigated. The results showed that the preferred orientations of Mg-Zr-O films were determined by lattice distortion of MgO crystal. The deposition conditions have great effects on the preferred orientations of Mg-Zr-O films. The preferred orientations affect voltage characteristics through affecting surface morphology of Mg-Zr-O films. A small amount of Zr solution in MgO can decrease firing voltage compared with using pure MgO film. Firing voltage is closely related with the [ ZrO2/(MgO+ZrO2)] ratio of evaporation source materials.

In this work low bandgap thienylenevinylene and phenylene vinylene copolymers, which possess either 3,4-ethylenedioxylthiophene (EDOT) groups (Polymer 1) or long alkyl side chains (Polymer 2) were investigated and compared in photoinduced electron transfer properties and photovoltaic performance. The results show that the interaction of the photoexcited polymers with an electron acceptor ([6,6]-phenyl C61 – butyric acid methyl ester (PCBM)) leads to charge generation and transfer for both polymers. We found that the long alkyl side chain in Polymer 2 instead of the EDOT group in Polymer 1 enhances the open circuit voltage ($V_{\it OC})$ but lowers the short circuit current ($I_{\it SC})$. On the other hand the long alkyl side chain in Polymer 2 significantly improves the solubility and enhances processability for solar cells fabrication. Optimization of the chemical structure of these low bandgap polymers could lead to a spectral improvement of photocurrent generation in organic solar cells.

Hydrogenated nanocrystalline silicon carbide (nc-SiC:H) thin films were prepared by reactive magnetron sputtering. Deposition was achieved in a plasma of argon (Ar) and an hydrogen (H2) gas mixture with various H2 dilution percentages (10–80% H2) at a fixed substrate temperature of 500 °C. In order to describe the local bonding and the relative proportion of the different complexes formed during growth, the films were investigated by means of Fourier Transform Infrared absorption and Raman spectroscopy. Other structural features were analyzed by AFM measurements, electron diffraction and high resolution transmission electron microscopy observations. Optical and electrical properties of the films were also characterized. This study shows that hydrogen dilution plays an important role on the microstructure of the films as well as on their properties. The highest refractive index was obtained for a 60% ratio of hydrogen in the plasma and the highest dark conductivity found was 2.03 × 10−4 Ω−1 cm−1. A close relationship between the Si-H bond content and the conductivity is confirmed.

We have fabricated heterojunction solar cells comprising active layers of perylene diimide (PDI) or perylene bisbenzimidazole (CONPER, conjugated perylene dye) as electron acceptor and ZnPC as donor. Bilayer solar cells were produced by successive evaporation of zinc phthalocyanine (ZnPC) and perylene diimide (PDI) or perylene bisbenzimidazole (CONPER) on glass substrates coated with indium doped tin oxide. Active layers with different thickness were evaporated. The bilayer cells were characterized under simulated AM 1.5 illumination (100 mW/cm2). The best results were obtained for the device structure of ITO/PEDOT/ZnPC (40 nm)/perylene bisbenzimidazole (60 nm)/Al (70 nm).

Reactively evaporated thin films of tantalum oxide are prepared on glass substrate, using electron beam heating, for optical applications. Firstly, the deposition was carried out at 0.20 nm/s, with substrate temperature of 200 °C, and oxygen flow rate was varied from 0.0 to 30.0 sccm to study the effect of flow rate on optical constants. The optical constants evaluated by using transmission data of the samples, with curve fitting, show a strong dependence on oxygen flow rate. Oxygen flow rate of 10.0 sccm has been found to give reasonably high index (n:2.11 at $\lambda =500$ nm) and low absorption of the order of 10−3 in most part of the desired spectrum (380–850 nm). However, for oxygen flow rates below 10.0 sccm and above 20.0 sccm the films have exhibited low index and comparatively high absorption. In the next step, deposition rates were varied from 0.10–0.30 nm/s with steps of 0.01, keeping oxygen flow rate and substrate temperature constant at 10.0 sccm and 200 °C respectively, to optimize the film properties. A variation in refractive index and extinction coefficient values is observed with varying deposition rates. An increase in refractive index (n:2.125 at $\lambda =500$ nm) with reduced absorption (“k” of the order of 10−4) is achieved over the entire spectrum for the film deposited at 0.10 nm/s. The film was found to be highly adherent to the substrate as revealed by qualitative adhesive tape peel test. Keeping in view the application of the work, calculation of optical constants was extended up to 1100 nm for the sample deposited at 0.10 nm/s. The results have shown nearly constant optical constant values over the extended range making the film useful over a broad spectral region. AFM studies show that the surface is extremely smooth and compact, giving average and rms roughness values of 5.51 and 7.174 Å respectively, for the studied area of $2.5~\mu \times2.5~\mu$. XRD and SEM studies carried out for structural analysis show that the film is generally amorphous with a sign that crystalline structure could be achieved at little higher substrate temperatures. The surface of the film is very smooth, free of voids, with the particle size in the range of 17–35 nm, calculated from SEM studies. The film has exhibited compact and dense structure. The work reported in this paper will be useful in tailoring the optical properties of Ta2O5 as per requirement.

Hybrid concepts based on a nanoscale combination of organic and inorganic semiconductors are a promising way to enhance the cost efficiency of solar cells through a better use of the solar spectrum, a higher aspect ratio of the interface, and the good processability of polymers. A new type of solar cells has been investigated. It is based on a heterojunction between regio-regular poly(3-hexylthiophene) as an organic electron donor and silicon as an inorganic electron acceptor. In a first step towards nano-structured devices, cells made of flat thin films of these materials have been studied as a model case of the heterojunction. The materials were characterized through ellipsometry and absorption spectroscopy. The devices were studied by means of their spectral response and their I-V characteristics. By combining these results, the contribution of each layer and the mechanisms of photocurrent generation are explained. The best cells to-date show a power conversion efficiency of 1.6% under AM 1.5 illumination, with a Voc of 0.704 V and a Jsc of 4.22 mA/cm2.

Using first-principles calculation for the electronic structures of nm-scale [0001] GaN freestanding films, it is found that the Ga-terminated surface (SGa) has a positive electrostatic potential, while the N-terminated surface has a negative electrostatic potential (SN), so that the energy bands tilt upwards from SGa to SN. Additionally, it is determined that an intrinsic self-regulated charge transfer across the film limits the electrostatic potential difference across the film, which renders the local conduction band energy minimum at SGa approximately equal to the local valence band energy maximum at SN. This effect is found to occur in films thicker than ~4 nm. If the dangling-bond/surface states at both SGa and SN are passivated by pseudo-hydrogen atoms, the tilt of energy bands is similar, though the cross-film potential is reduced due to the extra H5/4-Ga and N-H3/4 dipole layers.

Peculiar nuclear spin systems can be polarized at a level of thousands times the value obtained at thermal equilibrium, for instance by optical pumping. When concentrated, these systems create a sizeable average dipolar field which is experienced by any nuclear spin. We propose to use these distant dipolar fields for performing a polarization transfer in the Hartmann-Hahn conditions. We report the maximum enhancement value calculated using the spin temperature approach and first theoretical insights on the polarization transfer rate. Using, as an example, dissolved laser-polarized xenon, we show that by spin-locking both xenon spins and a proton spin of a solute, the polarization of the latter is enhanced. This is obtained without the existence of chemical interaction between the two entities and with characteristic rising time not directly correlated to the proton self-relaxation time. By its generality and its non-local feature, this approach could make possible nuclear magnetic resonance spectroscopy on very dilute systems.

Direct low temperature plasma (LTP) has been studied for some years now as an alternative eco-friendly technology for achieving shrink-resistant wool fabrics, its action being attributed to the varied active species existing in the plasma. In this paper, for the first time, the efficiency of a post-discharge plasma treatment on the shrink-resistance of wool fabrics has been evaluated. The density of active species present in the nitrogen plasma post-discharge (PD) has been determined by optical spectroscopy and their effects on the increase of hydrophilicity at different treatment times have been recorded through drop test and contact angle techniques. Analysis of the surface by X-ray Photoelectron Spectroscopy (XPS) has shown the increase in N and O – containing functionalities. The post-discharge has shown to be effective in reducing the area shrinkage of the fabrics and its effects have been compared to those obtained by direct LTP.

This paper presents the application of manganese dioxide to electromagnetic wave absorber. The effective permittivity was calculated by modified Rayleigh mixing formula, and the electromagnetic wave absorbing properties of composites with different volume fractions of manganese dioxide were investigated by the comparison of calculated and experimental values in 2–12 GHz frequencies. It is found that the pure manganese dioxide holds a high dielectric constant, which is a function of frequency. The manganese dioxide composites show high absorbing performance in low frequencies, and the calculated electromagnetic properties fit the experimental values for large volume fractions used in this study.

This paper presents a new method to simulate the properties of Frequency Selective Surface (FSS) composed of planar H-shaped fractals structure exhibiting multiple band gaps of electromagnetic waves. The FSS sample can be easily fabricated as that of the Printed Circuit Board (PCB). The electromagnetic characteristics of this H-shaped fractal structure were studied mainly by numerical simulation based on Finite Integration Technique (FIT). The simulation results present a direct image of surface currents when certain frequency electromagnetic waves incident on the surface of the sample, which is in a considerably good agreement with the experimental results. Based on the comparison of simulated and experimental result it is suggested that the planar H-shaped fractals structure has quasi-periodic multiple band gaps and the size can be significantly smaller than the relevant electromagnetic band gap wavelength.

We characterize a method of heat-assisted magnetic recording (HAMR), which may be applied for high-density probe storage system. The magnetic recording medium is a CoNi/Pt multilayered film, suitable for perpendicular recording. The heating source is the field emission current from a scanning tunneling microscopy (STM) tip, with pulse voltages added between the tip and the film. Writing shows a threshold voltage of 4 V. Marks with an average size of 165 nm were achieved for pulses above 4 V. A model of dynamic domain formation is applied to simulate the process of the formation of marks. The effect of domain wall forces is discussed. Simulation results agree with experiments well, without the need of taking domain wall forces into account.

A three-dimensional finite element method is applied to model a magnetic force control device. This device is based on the use of a magnetostrictive rod in order to control the magnetic force applied to a movable yoke. The paper introduces an original approach to model magnetostrictive phenomena and presents comparisons between numerical and experimental results.