In modern microelectronics progress has been made towards low power ultra large-scale integration (ULSI), and nano-structure devices such as single electron transistors and quantum dots. In this technology application of new materials, which includes high-κ dielectrics for the MOSFET transistors, with extraordinary purity and uniformity is required. Failure analysis and reliability investigations of such films very often requires highresolution local measurements of electrical surface parameters. This kind of experiments can be performed using conductive atomic force microscopy, which provides simultaneous measurement of surface topography and current ?owing through the investigated layer. In order to acquire reliable data, there was designed a precise measurement and control system, which included a low-noise current-to-voltage converter of picoampere resolution, a scanning stage with control electronics and a data acquisition system. In the paper we describe the architecture of the designed and applied experimental set-up. We also present results of simultaneous measurements of topography and current on gold and highly oriented pyrolytic graphite (HOPG).
Methane (CH4) sensitivity of zinc oxide (ZnO) thin film has been studied in the present work. The sensor element comprises
of a chemically fabricated ZnO semiconducting layer and a layer of palladium (Pd) as catalyst. The catalyst layer was formed on the surface of semiconducting ZnO following a wet chemical process from palladium chloride (PdCl2) solution. Fundamental features of a sensor element e.g. sensitivity, response time and recovery process has been studied. The effect of operating temperature on performance of the sensor material has been investigated and a choice of optimum temperature was made at around 200oC. The sensor element exhibited reasonable sensitivity of about 86% at this temperature in presence of 1 vol% methane (CH4) in air.
GZO/IZO semiconductor thin films were prepared on the ITO substrate via sol-gel spin coating method for using in the dyesensitized solar cells (DSSCs). For this purpose, GZO and IZO thin films were optimized by the percentage of doping gallium and indium in zinc oxide and were studied their electrical, optical and structural properties. After that, the layers with the best performance were selected for use in the DSSCs. The concentration of all solutions for spin coating processes was 0.1 M and zinc oxide has been doped with gallium and indium, with different doping percentages (0, 0.5, 1, 2 and 4 volume percentage). So, by studying the properties of the fabricated thin films, it was found the films with 0.5%GZO and 0.5%IZO have the best performance and hence, the optimized dual-layer (0.5% GZO/0.5% IZO (GIZO)) were prepared and studied their electrical and optical properties. The synthesized optimized dual-layer film was successfully used as the working electrode for dye-sensitized solar cells. The sample with 0.5%IZO shows the 9.1 mA/cm2 short-circuit current density, 0.52 V open circuit voltage, 63% fill factor and 2.98% efficiency.
Numerous films, especially reinterpretations of the Gospel, can be read as loci theologici. Nevertheless, it’s important to recognize that the commercially motivated interest of filmmakers has its theological consequences: a resulting challenge is the catechetical use of apocryphal films in the pastoral praxis of the Church. The paper recalls main documents of the Church, relating to the cinema, stressing the absence of official teaching on the cinema in the last 20 years. Films, produced with commercial motivation, are often kitsch; it’s a result of tendencies to gain the possibly large audiences and to fulfill their expectations. An analysis of selected films (e.g. The Passion of the Christ and Son of God) indicates that the kitschy audiovisual apocrypha, superficial, emotional and lacking of authenticity, become a false filmic transformation of the message of the Bible. The paper postulates the need of constructing a theology of film: its object could be audiovisual texts, which extra-ecclesial theologies influence religious imagination and thinking of the viewers.
The aim of this work was to produce a thin SnO2 film by a technique combining the sol-gel method and electrospinning from a solution based on polyvinylpyrrolidone and a tin chloride pentahydrate as a precursor. The spinning solution was subjected to an electrospinning process, and then the obtained nanofiber mats were calcined for 10 h at 500°C. Then, the scanning electron microscopy morphology analysis and chemical composition analysis by X-ray microanalysis of the manufactured thin film was performed. It was shown that an amorphous-crystalline layer formed by the SnO2 nanofiber network was obtained. Based on the UV-Vis spectrum, the width of the energy gap of the obtained layer was determined.
Thin films of crystallized LaCoO3 were grown on Si substrate by Pulsed Laser Deposition at different temperatures (750°C, 850°C and 1000°C). The structural characterization of the LaCoO3 thin films was done by combining several techniques: Scanning Electron Microscopy (SEM), Atomic Force Microscope (AFM), Transmission Electron Microscopy (TEM) and Grazing Incidence X-Ray Diffraction (GIXRD). The thin films crystallized in the expected rhombohedral phase whatever the deposition temperature, with an increase of crystallite size from 70 nm at 750°C to 100 nm at 1000°C, and an average thickness of the thin films of less than 200 nm. At 850°C and 1000°C, the thin films are crack-free, and with a lower number of droplets than the film deposited at 750°C. The grains of LaCoO3 film deposited at 850°C are columnar, with a triangular termination. At 1000°C, an intermediate layer of La2Si2O7 was observed, indicating diffusion of Si into the deposited film.
This work presents a theoretical study for the distribution of nanocomposite structure of plasmonic thin-film solar cells through the absorber layers. It can be reduced the material consumption and the cost of solar cell. Adding nanometallic fillers in the absorber layer has been improved optical, electrical characteristics and efficiency of traditional thin film solar cells (ITO /CdS/PbS/Al and SnO2/CdS/CdTe/Cu) models that using sub micro absorber layer. Also, this paper explains analysis of J-V, P-V and external quantum efficiency characteristics for nanocomposites thin film solar cell performance. Also, this paper presents the effect of increasing the concentration of nanofillers on the absorption, energy band gap and electron-hole generation rate of absorber layers and the effect of volume fraction on the energy conversion efficiency, fill factor, space charge region of the nanocomposites solar cells.
Stable dispersion of antimony-doped tin oxide nano-powder was prepared by wet attrition process by comminuting aggregated ATO nano-powder using the titanate coupling agent as a dispersant to form the chemisorbed layer on the particle surface. The feed solution of the ATO dispersion and PVP was prepared for electro-spun fibers on the glass substrate. The surface resistance of the fibrous ATO film after electrospinning for 30 minutes was in the order of 105 Ω/□, which is sufficient for anti-static coating. The optical transmittance of ATO fibers was confirmed by measuring the visible light transmittance.
Ice formed on radome surfaces causes communication disruption due to radio-frequency interference (RFI), which reveals the importance of de-icing systems for radomes. As a radome de-icing application, in this work, carbon nanotube (CNT) thin films were fabricated using a spray-coating method, and influence of process parameters on RF transmittance and electrothermal properties was investigated. With the increase of spraying time, sheet resistance of the fabricated film decreases, which results in a decrease of the RF transmittance and improvement of the heating performance. Also, the de-icing capability of the fabricated CNT film was evaluated at –20oC, and efficient removal of ice under cold conditions was demonstrated.