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CsI:Tl is a very efficient scintillator which is widely used in X-ray detection. However, it tends to deliquesce when exposed to the humid air. Thus, in this paper, we examined the change of the morphology, growth orientation and the fluorescent property of CsI:Tl thin film when it was exposed to the humid air with different humidity. It turned out that when CsI:Tl thin film was exposed to the humid air, its grain size became bigger, its preferential growth orientation changed and its light conversion property decreased. [ABSTRACT FROM AUTHOR]

In this paper, we report an electrochromic device (ECD) using novel silica/ poly(3,4-ethylenedioxythiophene) (SiO2/PEDOT) core/shell nanoparticle film as electrode. The SiO2/PEDOT core/shell nanocomposite film was prepared by a facile in situ chemical oxidative polymerization method. Compared with the pure PEDOT film, the SiO2/PEDOT nanocomposite film exhibits shorter response time (1.8 s for bleaching and 1.4 s for coloring), higher coloration efficiency (247.6 cm2/C) and better cycling stability (sustaining 81.8% of its initial optical contrast after switching 5000 s). The improved electrochromic performances are attributed to the core/shell nanostructures, which can make ion diffusion easier and provide larger surface area for charge-transfer reactions. Moreover, the ECD based on SiO2/PEDOT film also exhibits good electrochromic performances and has potential applications in smart windows, automobile anti-glare rearview mirrors and energy saving displays. [ABSTRACT FROM AUTHOR]

This paper reports the structure, microstructure, domain imaging and magnetostrictive properties of Fe50Co50 thin grown on Si < 100 > substrates with different thicknesses namely 40, 80, 100 and 120 nm. Structural studies revealed that the films are crystalline in nature with bcc type structure. Magnetization studies exhibited predominant in-plane magnetic anisotropy for all the films. In addition to this films grown with higher thicknesses also showed co-existence of out-of-plane magnetic anisotropy along with in-plane magnetic components. Angle dependent hysteresis measurements indicated presence of weak uni-axial magnetic anisotropy along the plane for all the films. Longitudinal magneto-optic Kerr microscopy studies revealed nucleation of reverse domains for the film grown with low thickness. Wide band domains with few zig-zag branched features have been observed for the films grown with higher thicknesses. Magnetic force microscopy investigations along the out-of-plane direction showed increase in magnetic phase contrast with increase in film thicknesses. Magnetostriction derived from the deflection measurements are found to decrease with increase in film thicknesses. Presence of competing anisotropies has been found to be prominent reason for the decrease in the magnetostriction with increase in film thickness. [ABSTRACT FROM AUTHOR]

In this paper, various possible materials for the gate dielectric of nc-Si top-gated thin film transistor (TFT) and their material properties like dielectric constant, bandgap, conduction band offset and interface trap density are taken into consideration and Ashby's, VlseKriterijumska Optimizacija I Kompromisno Resenje in Serbian (VIKOR) and Technique for order preference by similarity to ideal solution (TOPSIS) approaches are applied to select the most suitable gate dielectric material. The analysis results suggest that SiN is the most suitable gate dielectric material for the better performance of nc-Si top-gated TFT. The results shows good agreement between Ashby's, VIKOR and TOPSIS approaches. [ABSTRACT FROM AUTHOR]

In the last decade, as semiconductor industry was approaching the end of the exponential Moore's roadmap for device downscaling, the necessity of finding new candidate materials has forced many research groups to explore many different types of non-conventional materials. Among them, graphene, CNTs and organic conductors are the most successful alternatives. Finding a material with metallic properties combined with field effect characteristics on nanoscale level has been always a dream to continue the ever-shrinking road of the nanoelectronics. Due to its fantastic features such as high mobility, optical transparency, room temperature quantum Hall effect, mechanical stiffness, etc. the atomically thin carbon layer, graphene, has attracted the industry's attention not only in the micro-, nano-, and opto-electronics but also in biotechnology. This paper reviews the basics and previous works on graphene technology and its developments. Compatibility of this material with Si processing technology is its crucial characteristic for mass production. This study also reviews the physical and electrical properties of graphene as a building block for other carbon allotropes. Different growth methods and a wide range of graphene's applications will be discussed and compared. A brief comparison on the performance result of different types of devices has also been presented. Until now, the main focus of research has been on the background physics and its application in electronic devices. But, according to the recent works on its applications in photonics and optoelectronics, where it benefits from the combination of its unique optical and electronic properties, even without a bandgap, this material enables ultrawide-band tunability. Here in this article we review different applications and graphene's advantages and drawbacks will be mentioned to conclude at the end. [ABSTRACT FROM AUTHOR]

The preparation of nanoporous thin film of metal-organic framework (MOF), Cu-BTC [1,3,5-benzenetricarboxylate or trimesate (BTC)], on the copper plate electrode as dielectric layer of the capacitive sensor was achieved by electrochemical in situ synthesis and film growth. An ionic liquid (IL), 1-methyl-3-octylimidazolium chloride as conducting salt, was used and aid synthesis in the electrochemical synthesis procedure. The structure and morphology of MOF film were properly characterized using scanning electron microscopy, Fourier-transform infrared spectroscopy, X-ray diffraction analysis and BET techniques. The fabricated sensor was used for the humidity measurement at ppm level using the parallel plates' capacitive sensor structure. Capacitance variations in the presence of humidity at concentration range of 20-100 ppm was investigated using the fabricated sensor. The performances of the sensor have been examined by measuring the capacitance changes using a LCR meter [inductance (L), capacitance (C), and resistance (R)]. Variations of capacitance versus concentration were linear in the range of humidity concentrations which was used here. Sensitivity of the fabricated sensor was 1.13 pF/ppm. Limit of detection (LOD) of the fabricated sensor calculated as low as 5.45 ppm. n-Hexane and toluene vapors as nonpolar analytes were used to investigate the selectivity of the sensor. [ABSTRACT FROM AUTHOR]

In this work a double-layer photoanode composed of TiO2 nanocrystals (NCs) and hollow spheres (HSs) was applied in CdS:Mn sensitized solar cells. TiO2 NCs with dominant size of 25 nm were synthesized by a facile hydrothermal method. TiO2 HSs were also prepared through the liquid phase deposition (LPD) of TiO2 on carbon spheres followed by a calcination process. The double electron transport layer of quantum dot sensitized solar cells (QDSCs) was formed of a nanocrystalline TiO2 layer covered by a light scattering HSs film. The corresponding thicknesses were also controlled to be about 10 µm and 7 µm, respectively. The sensitization of photoanode with Mn doped CdS NCs were carried out by a successive ionic layer adsorption and reaction (SILAR) technique. The apparent MnMn+Cd molar ratio was altered in a wide range of 0-9%. The corresponding QDSCs were fabricated and the doping process was optimized for the improved power conversion efficiencies. According to the results, the QDSC with a double-layer photoanode sensitized with MnMn+Cdratio of 7.0% showed the maximum efficiency of 3.26%. This value was increased about 61% and 18% compared to those of the reference cells with single nanocrystalline and double-layer photoanodes sensitized with un-doped CdS NCs. The reason was addressed due to the higher light scattering and Mn related electron energy states within the bandgap energy of CdS NCs and the improved electron transport property of the cell. A ZnS passivating layer was also utilized as the electron blocking layer on the surface of the optimized doped photoanode with different thicknesses. It was shown that the highest energy conversion efficiency of 3.55% was achieved for three cycles of ZnS SILAR deposition. [ABSTRACT FROM AUTHOR]

Sodium antimonate glass ceramics with different concentrations of Au2O3 were synthesized. The prepared samples were characterized by XRD, XPS, SEM and TEM techniques. These studies have revealed that the samples consist of multiple crystalline phases composed of Sb3+, Sb5+, Au3+ ions, and Au0 particles; moreover these studies have indicated growing proportion of Au0 particles and Sb5+crystal phases (Na2Sb2O6) with increase of Au2O3 concentration. IR and Raman spectral studies have pointed out an increasing degree of polymerization of the glass network with increase of Au2O3 content while optical absorption studies indicated surface plasmon resonance effects. Nd: YAG laser (λ = 1320 nm and pulse width 8 ns) was used for inducing third harmonic generation (THG) signal. Later, THG signal intensity of Nd: YAG laser (λ = 1064 nm and pulse width of 20 ns) vs fundamental beam power density was recorded. The results indicated the maximum intensity for the samples containing a low concentration of Au2O3. For inducing piezo-optical effects, Nd: YAG laser (λ = 1064 nm) and its doubled frequency beam λ = 532 nm (with simultaneous mechanical pressure) were used. The cw He-Ne laser of 20 mW (with beam diameter about 0.5 mm) was used as probing beam for measuring the piezo-optical effects in the photo-polarized samples. The variation of the intensity of the THG beam and piezo-optical coefficients were found to be the maximal for the samples mixed with small quantities of Au2O3. The detailed analysis of XRD, SEM, EPR, IR, optical absorption spectral results suggested that concentrations of Na3SbO3 and also Au2O3 crystal phases are maximal in these samples and are responsible for the maximal photoinduced effects, while the increasing presence of Na2Sb2O6 crystal phases and Au0 metallic particles are found to be hindrance for generation of third harmonic beams and also piezo-optical effects. Overall, the obtained results of nonlinear optical (NLO) and piezo-optical studies indicated that Na2O-Sb2O3 glass ceramics containing small traces of Au2O3 are useful for considering them for nonlinear optical triggering devices and piezo-electric devices. [ABSTRACT FROM AUTHOR]

Thin films of yttrium oxide phosphor doped with trivalent europium ion (Y2O3:Eu3+) are grown on a quartz fabric substrate by using electron beam evaporation with different electron beam currents from 80 to 170 mA. The dependence of morphological structure, crystal structure, luminescent properties and chromaticity coordinates of Y2O3:Eu3+ thin films on the electron beam current is thoroughly analyzed. The experimental results show that the thickness of the films is significantly increased from 0.69 to 1.68 µm when the deposition current is increased from 110 to 170 mA. Improvements in the surface morphological components, such as spherical-shaped particles and a more dense topography, can be found when the films are deposited with a current of 140 mA. The predominant orientation of the Y2O3:Eu3+ thin films transforms from the (400) to (222) crystal face when the current is increased from 110 to 140-170 mA. The maximum crystallinity of the films occurs when the deposition current is used at 140 mA. The luminescent spectra results indicate that the improved morphology, inceased film thickness and enhanced crystallinity can contribute to the better luminescent properties of the Y2O3:Eu3+ thin films. The highest emission brightness is obtained when the Y2O3:Eu3+ thin films are prepared with a deposition current of 140 mA, and the luminescent intensity is increased by 6317% when the deposition current is increased from 80 to 140 mA. [ABSTRACT FROM AUTHOR]

0.65Pb(Mg1/3Nb2/3)O3-0.35PbTiO3 (PMN-PT) thin films were deposited on (111)Pt/Ti/SiO2/Si substrates via the chemical solution deposition. Both of the annealing process and additive methanamide play an obvious part in the structure and electrical properties of PMN-PT films. The optimized high-qualitied PMN-PT thin film in present work is fabricated with the methanamide in the precursor and annealed at 650 °C for 20 min. The film exhibits pure perovskite phase and superior ferroelectricity. The saturation polarization Ps and remanent polarization Pr are 52.1 µC/cm2 and 18.7 µC/cm2 at 500 kV/cm with 1000 Hz. It also shows low leakage current density of approximately 1.0 × 10− 8 A/cm2 at 200 kV/cm. [ABSTRACT FROM AUTHOR]

Low-stress design of bonding technology with a sandwich structure of sintered Ag and tungsten (W) thin film was developed for SiC power die-attached modules. The die-attached bonding layer was designed as sintered Ag/W/sintered Ag structure. Experiment results show that the initial bonding strength was larger than 65 MPa for this die-attached structure and larger than 35 MPa with a thermal shock test from − 50 to 250 °C for 1000 cycles. These results are largely better than that almost all sintering Ag technology reported in previous studies. Furthermore, the sandwich structure also compared with the sintered Ag structure which just using sintered Ag paste as bonding layer. The thickness of Ag paste is set as 100, 200 and 500 µm in the sintered Ag structure. The results show that the initial bonding strength of sintered Ag structure was about 60-70% of the value of W sandwich structure and about one-third of that after 1000 cycles. X-ray and SEM observation revealed that sandwich structure significantly decreased the size of crack extension in the sintered Ag layer during the thermal shock test. Finite element analysis reveal that the shear stress at the pore location of sandwich structure decreased to almost half values of the sintered Ag structure with the thickness of sintered Ag of 500 µm, and decreased almost 20% compared with the thickness of sintered Ag of 100 µm. The bonding technology with the W sandwich structure should be an attractive for low stress design in SiC power die-attached modules, which significantly increased its function for long-term high temperature applications. [ABSTRACT FROM AUTHOR]

Ga-doped ZnO (GZO) thin films with different Ga contents (1, 2, 4, 3, and 5 at.%) were successfully deposited on glass substrates using a spin-coating process. The temperature dependent electrical conductivity and room-temperature Hall effect measurements were performed for the films. The variation of electrical conductivity with Ga content was well explained by considering the change in the inelastic diffusion length of electrons. The critical value of carrier concentration for the metal-insulator transition was estimated as 1.77 × 1018 cm−3 for GZO. The critical value of Ga content, where Ga as a donor source becomes ineffective, on the order of 5.25 at.% was obtained. [ABSTRACT FROM AUTHOR]

In the present work, we have demonstrated the micro-supercapacitor behavior of titanium vanadium nitride thin films fabricated on stainless steel substrates by a pulsed DC magnetron sputtering technique. The microstructural characterization from X-ray diffraction (XRD) reveals the FCC structure of TiVN thin films with a preferred (200) orientation. A faceted morphology with square-edge shaped dense grains of the thin films is observed from field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) images. Ion scattering spectroscopy (ISS) and X-ray photoelectron spectroscopy (XPS) was used to determine the surface compositions and confirmed the absence of impurities. The specific capacitance (Csp) of the electrode material was evaluated by cyclic voltammetry (CV). Galvanostatic charge-discharge (CD) test and the electrochemical impedance spectroscopy (EIS) measurements were also performed. The electrochemical result of fabricated TiVN displays a supercapacitive behavior. A maximum Csp of 69 F/g (volumetric capacitance of 155.94 F/cm3) is obtained from both CV and CD studies. The experimental results reveal that the sputtered TiVN thin films area promising electrode material for electrochemical micro-supercapacitors. [ABSTRACT FROM AUTHOR]

In the present work, ruthenium incorporated cobalt oxide thin films were synthesized on stainless steel substrates using potentiodynamic electrodeposition via aqueous route. The aim of the Ru incorporation is to ameliorate the electrochemical performance of the pristine cobalt oxide thin film. XRD, FESEM and TEM were used for the structural and morphological characterizations while cyclic voltammetry (CV) and chronopotentiometry were used for the electrochemical characterizations of the prepared samples. The XRD patterns of the deposited samples shows polycrystalline face centered cubic and tetragonal type crystal structures for Co3O4 and RuO2 respectively. TEM study confirms compact granular type morphology with crystalline nature as depicted from SAED analysis. Prepared samples show nearly hydrophobic nature. CV study reveals hybrid capacitive behavior with optimum specific capacitance 296.55 F/g at the scan rate 2 mV/s in 1 M KOH. Ru incorporation showed improvement in the electrochemical stability achieving 94.10% retention after 1000 cycle at the scan rate 100 mV/s in 1 M KOH. Electrochemical impedance spectroscopy (EIS) reveals the 0.88 Ω internal resistance of optimized electrode. [ABSTRACT FROM AUTHOR]

In this study, uniform BaO-BO-SiO glass coatings on micro Cu powders with different glass/Cu ratio were prepared by sol-gel method. The pastes prepared with the glass-coated Cu powders were screen printed on low temperature co-fired ceramic (LTCC) substrate. Then the dry films on substrate were binder-burned-out at 400 °C in air and co-fired at 910 °C in N atmosphere. During the binder-burning-out process, the oxidization of the films with 9 and 11 wt% glass was slight because of the improvement of oxidization resistance of the glass-coated Cu powders. Moreover, the sintered film with 9 wt% glass coating showed no crystal phase of copper oxide and had small sheet resistance of 1.3 mΩ/□, which can be used as good conductive thick film on LTCC substrate for microelectronic packaging. [ABSTRACT FROM AUTHOR]

Sulfide based phosphors such as CdS and ZnS have been potential candidates for their promising applications in various optoelectronic applications. However, much of these applications demand a reproducible, reliable and controllable synthesis method that takes special care of their functional properties. It is well established that (Cd-Zn)S films possess properties between those of CdS and ZnS. Since, their addition produces a common lattice in which band structure has a larger band-gap than CdS, it makes the material more attractive for fabricating display devices. With Cu doping, it can be used as a green and blue emitting active layer. Here in, we present a critical review on the structural and optical properties of pure and Cu-doped (Cd-Zn)S films prepared by different techniques. The effect of Cu doping has been reviewed in the light of dependence of structural and optical properties on various parameters, such as Cd/Zn ratio, molar concentration, pH variation, temperature, capping legends and deposition time. The possibility of these films to be used for electrical and thermo-electrical applications is also discussed. [ABSTRACT FROM AUTHOR]

The existing thin film technology involves rare earth and toxic materials. CuZnSnS, its selenide and sulfo selenide analogues have acquired as the most promising alternate absorber material group in thin film technology due to the abundance and non toxic constituent elements. We present a facile, green and low cost method for synthesis of CZTS/(Se) films. Precursor powders using Cu, Zn, Sn, S and Se, was prepared by ball milling. Starting with ball milled metallic precursor powders we synthesized kieserite thin films by doctor blade coating process and subsequent annealing. Doctor blade coating method is one of the cheapest non toxic non vacuum based chemical deposition processes. A comparative study of ball milled powder and films prepared from the precursors has been presented and interesting aspects of structure, morphology and composition were explored after ball milling, and films formed after annealing. Chalcogens (S or Se) plays an important role in the construction of tetragonal phase. A combined TGA-DSC, X-ray diffraction, Raman, TEM, EDX and UV-Vis-NIR study showed marked change in film property after annealing. [ABSTRACT FROM AUTHOR]

In order to investigate Si doping effect on the structure and properties of GaO thin films, films with different Si content were grown by pulsed laser deposition (PLD) on sapphire substrates at 500 °C. Carrier density of 9.1 × 10 cm and conductivity of 2.0 S cm have been observed for 1.1 at.% Si-doped film. Further increase of the Si content leads to the decrease of the carrier density. Atomic force microscope and spectrophotometer show that the obtained films have very smooth surface and high transmittance. X-ray diffraction reveals that films with Si content lower than 4.1 at.% are of high (-201) oriented monoclinic structure. Our work shows that PLD is ideal candidate for growing conductive Si-doped β-GaO films. [ABSTRACT FROM AUTHOR]

p-type nitrogen doped ZnMgO (x = 0.15) thin films were prepared on n-type silicon substrates by RF sputtering. Plasma-immersion-ion technique and rapid-thermal process were used to implant nitrogen and annealing (700-1000 °C) of these films respectively. Annealed samples at 700, 800, 900 and 1000 °C showed effective improvement of the structural and optical properties. X-ray diffraction spectra showed improvement in <002> orientation of films with increase in annealing temperatures. In Raman spectra, the peak at 436 cm corresponds to E phonons mode of ZnMgO wurtzite structure and FWHM of this peak decreases with increase in annealing temperature, indicating improvement in crystalline quality. The scanning electron microscopy results demonstrate that nitrogen-implanted ZnMgO film annealed at 1000 °C has better morphology in comparison to other films. Low-temperature (15 K) photoluminescence measurements revealed acceptor-bound exciton peak at 3.45 eV and donor-bound exciton peak around 3.52 eV. Increased intensity of acceptor-bound exciton peak with increasing annealing temperature proves that nitrogen implantation and subsequent annealing increase the acceptor concentration in the film, indicating tendency for p-type conduction at higher annealing temperature. The film annealed at 1000 °C was observed to produce only acceptor-bound exciton emission and no donor-bound exciton emission was occurred. Hall-effect measurements showed p-type conductivity for annealed films in temperature range at 800-1000 °C. The acceptor level at 3.45 eV in PL spectra is responsible for this p-type conduction in these films. The highest hole concentration of 1.91 × 10 cm has been achieved for film annealed at 1000 °C. [ABSTRACT FROM AUTHOR]