Results 1 - 10 of 248
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[en] In this paper, the recent research progress on triphenylamine (TPA)-based donor-acceptor (D-A) amorphous polymers including our developed polymers is reviewed. TPA has three-dimensional branched structures and can provide D-A polymers containing D and A units in the main chain or side chain. The use of TPA-based amorphous polymers in the fabrication of organic photovoltaics (OPVs) offers great advantages over the use of a polycrystalline film in terms of high reproducibility of the OPV performance. The amorphous polymer design using TPA, therefore, indicates a promising direction for the development of new donor materials in OPVs
[en] Cathodic protection is intensively used on steel pipes in petroleum and gas industries. It is a technique used to prevent corrosion which transforms the whole pipe into a cathode of a corrosion cell. Two types of cathodic protection systems are usually used: 1) the galvanic protection systems which use galvanic anodes, also called sacrificial anodes being electrochemically more electronegative than the structure to be protected and 2) the imposed current systems, which through a current generator will deliver a direct current from the anode to the structure to be protected. The aim of this work is to design a cathodic protection system of a pipe by imposed current with auxiliary electric solar energy. (O.M.)
[en] Lanthanum aluminate (LaAlO3; LAO) film was grown on p-Si (100) substrate by spin-coating technique. And then electroless nickel plating was performed on top and bottom of as-deposited LAO film as electrodes. The crystal structure and phase formation of LAO powder were examined by X-ray diffraction (XRD). Film thickness and surface morphology were examined by SEM. Electrical characteristics (I-V) was studied to evaluate the photovoltaic behavior of LAO film.
[en] Full text: Grand challenges to create new front metallization techniques in photovoltaics focus considerable attention on LIFT approach. This alternative method aims to overcome the limitations of the well-established and mature screen-printing technique. Such limitations are for instance: restrictions in the grid pattern design, high temperature steps, and poor aspect ratio of the line contact. Although different new front contact metallization concepts have been studied like ink-jet printing, light induced plating or photolithography, etc., most of them require relatively complicated or expensive processing steps and are not attractive for industrial production. As a result it is desirable to find innovative metallization techniques to improve the cell efficiency without significantly increasing the cost. As mentioned before, a very promising metallization concept, which can be implemented in production lines, is based on a single-step LIFT from thick film Ag inks. But many challenges remain before obtain high-quality, robust and high performance LIFT contacts formation and it is required a fully theoretical and experimental assessment. With this intention the direction which is followed by Lasers, Plasmas and Photonic Processes Institute (LP3) was to develop and optimize LIFT technique to create front side metallization for photovoltaic applications. This paper presents the results of a study of LIFT technique to create high quality and good relation aspect contacts prepared from thick Ag-based inks. The process provides precision deposits of silver inks films onto a working substrate. The beam of a picosecond pulsed laser (Continuum Leopard SS-10-SV Nd:YAG, 10hz, 50ps, at 355 nm third harmonic) is imaged on the donor. The receiver substrates are located on micrometer translation systems (x, y, z). The laser pulses interact with the liquid film and propel the ink away from the substrate. The ejected material exhibits different regime of ejection depending of the viscosity of the liquid. We focus on this paper on the ejection of high viscosity paste. For successful LIFT front contact formation a full understanding of the fluid dynamics of the accelerating ink films is critical. Finally, complete morphological study was carried out with Scanning Electron Microscopy (SEM), Energy Dispersive X-ray (EDX) spectrometry and Confocal microscopy. The fluid dynamics of the ejected material has been studied by time-resolved imaging technique. The results and fundamental investigations of the processes underlying the technique illustrate the role played by different laser parameters in the evolution of microstructure and electrical properties of the deposited material. (author)
[en] TiO2-ZrO2 fine binary oxide was prepared by mechanochemical milling process to be homogeneous binary oxide powder. TiO2-ZrO2 paste was deposited on microscopic glass slide by rolling. It was immersed in the henna solution and annealed at 100C for 2h. It was deposited onto another glass slide and used as counter electrode (second electrode). Two glass slides were offset and two binder clips were used to hold the electrodes together. Photovoltaic properties of TiO2-ZrO2 cell were measured and it was expected to utilize the dye sensitized solar cells application.
[en] Polymers are used as insulating materials for electric and electronic equipment research and development efforts on polymers have now made available a multitude of products for the satisfaction of electric and electronic applications. Polymeric materials possess superior chemical and physical properties as structural mechanical, optical, insulating, electrical, and electronic. In addition, they are low cost, light, and high toughness materials. These material characteristics make polymers play an important role in photovoltaics industry as candidate materials, moreover, polymeric epoxies with excellent dielectrics, and thermal properties, superior adhesion and good chemical and moisture  are very good as PV module gland and sealer. This paper is devoted to polymers exciting development in the field of photovoltaic converters, and module reinforcement and protection with emphasis on module encapsulation clarification and choice.(author)
[en] The structural, optical, and optoelectronic properties of copper zinc tin sulfide (CZTS) films, deposited by a nonvacuum nanoparticle based approach were studied as a function of different annealing temperatures. The CZTS films for photovoltaic applications were deposited using the doctor blading method using an ink prepared with nanoparticles synthesized using the solvothermal method. Deposited films were annealed at different temperatures in N2-S atmosphere. The films were characterized using different tools such as X-ray diffraction, scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDXS), ultraviolet-visible spectroscopy, Raman spectroscopy, and photoconductivity. The results showed that the kesterite phase was formed in the temperature range between 400 and 550 oC. At temperatures beyond 500 oC, many peaks of binary and ternary phases were detected, probably because of the decomposition of the kesterite layer. The cross section SEM images showed that the film is compact; however, there are isolated voids. The EDXS estimated chemical composition was found to vary with annealing temperature; the nearly stoichiometric film was obtained when annealed at 450 oC. The optical band gap of the stoichiometric film was 1.6 eV, and it showed photoconductivity. (author)
[en] The objective of this project has been to create a photovoltaic roofing product, the Electra-Slate, that appears physically and dimensionally to conform with a standard pattern, but is designed in a way that any roofer could install the device with total safety on an existing truss, rafter, felt and batten construction roof without additional training and supervision. This has been achieved by developing new concepts in high voltage Amorphous Silicon plate, with in built series connections, and by making an inboard parallel bus connection system, which is self connecting during normal roofing placement. The remaining barriers to be overcome are further reductions in cost and increased output. These two effects combine to form the barrier of installed cost/kilowatt. However it is clear that cost/m2 is already more competitive for this type of product than for a 'PV' module type of product. (author)