26 research outputs found

    Optimization and performance of Space Station Freedom solar cells

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    High efficiency, large area and low cost solar cells are the drivers for Space Station solar array designs. The manufacturing throughput, process complexity, yield of the cells, and array manufacturing technique determine the economics of the solar array design. The cell efficiency optimization of large area (8 x 8 m), dielectric wrapthrough contact solar cells are described. The results of the optimization are reported and the solar cell performance of limited production runs is reported

    Silicon solar cells for space use: Present performance and trends

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    A technology assessment of present performance levels and current fabrication methods and designs is presented

    Development of high efficiency (14 percent) solar cell array module

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    Most effort was concentrated on development of procedures to provide large area (3 in. diameter) high efficiency (16.5 percent AM1, 28 C) P+NN+ solar cells. Intensive tests with 3 in. slices gave consistently lower efficiency (13.5 percent). The problems were identified as incomplete formation of and optimum back surface field (BSF), and interaction of the BSF process and the shallow P+ junction. The problem was shown not to be caused by reduced quality of silicon near the edges of the larger slices

    Development of High Efficiency (14%) Solar Cell Array Module

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    High efficiency solar cells required for the low cost modules was developed. The production tooling for the manufacture of the cells and modules was designed. The tooling consisted of: (1) back contact soldering machine; (2) vacuum pickup; (3) antireflective coating tooling; and (4) test fixture

    High efficiency, long life terrestrial solar panel

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    The design of a high efficiency, long life terrestrial module was completed. It utilized 256 rectangular, high efficiency solar cells to achieve high packing density and electrical output. Tooling for the fabrication of solar cells was in house and evaluation of the cell performance was begun. Based on the power output analysis, the goal of a 13% efficiency module was achievable

    Development of high efficiency (14%) solar cell array module. Second quarterly report, March 15-July 15, 1979

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    Work on the development of large area, high efficiency P/N solar cells is described. The best performance achieved to-date on 3'' diameter cells is 15.6% at AM1 and 28/sup 0/C. Factors contributing toward the poor performance have not been identified and isolated. Work is continuing. Minor modifications have been incorporated in the modular design. The 120 cells will be connected 8 in parallel and 15 in series to enhance the reliability of the modules. As a result of the changes, two junction boxes will be required as the P and N terminals will come out from the opposite sides of the module. Designs for back contact soldering machine, vacuum pick-up, AR coating tooling, and test fixture have been completed. Fabrication of tooling has begun

    Development of high efficiency (14%) solar cell array module. Third quarterly report, July 15, 1979-November 15, 1979

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    Most effort was concentrated on development of procedures to provide large area (3'' diameter) high efficiency (approx. 15.5% AM1, 28/sup 0/C) P/N solar cells. These efficiencies had been obtained for 2 x 2 cm area cells, but tests showed that the problem was not reduced silicon quality near the edges of the larger slices. The problems were in optimizing the back-surface field (BSF) process, and its possible interaction with the shallow P+ layer formation. Towards the end of this reporting period a promising process sequence had been identified and is being tested. The module design has been finalized. One hundred and twenty (120) cells will be connected eight (8) in parallel and fifteen (15) in series. The designs and tooling phases have been completed and are awaiting completion of the cells

    Synthesis of copper-silver doped hydroxyapatite via ultrasonic coupled sol-gel techniques: structural and antibacterial studies

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    Fabrication of hydroxyapatite (HA) via doping with metal ions to enhance its antibacterial properties has attracted much interest. The present study aims to synthesize copper-silver doped hydroxyapatite particles (Cu-Ag doped HA) with an improved antibacterial activity through a sol-gel technique coupled with ultrasonic irradiation. The doping materials consist of Cu2+ and Ag+ ions with precursor molar ratios of 0.0, 0.25, 0.50, 0.75 and 1.0. The physicochemical properties of Ca9.0Cu1.0-xAgx(PO4)6(OH)2 samples were investigated using X-ray diffraction, Fourier-transform infrared spectroscopy (FT-IR), and transmission electron microscopy coupled with energy dispersive X-ray analysis (TEM-EDS). Characterization studies revealed that Cu2+ and Ag+ ions were incorporated into a hexagonal framework of HA. The main functional groups were identified as hydroxyl (OH−) and phosphate (PO43−) moieties. Their morphologies were rod-shaped with various diameters and particle size distributions, depending on the molar ratio of Cu2+ to Ag+. Antibacterial activity was evaluated using an agar well diffusion method against Staphylococcus epidermis, S. aureus, Bacillus subtilis, B. cereus, and Pseudomonas aeruginosa. It was found that Cu-Ag doped HA is an effective antibacterial agent. Ca9.0Cu0.5Ag0.5(PO4)6(OH)2 showed the best antibacterial performance against all bacterial strains with inhibition zones ranging from 13 to 17 mm, indicating its suitability as an antibacterial material in biomedical applications

    Automated linear concentrator cell module assembly /

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    "Prepared for Sandia National Laboratories under contract No. 13-2354.""Printed August 1980."Prepared by Sandia National Laboratories for the U.S. Department of Energy.Sponsored by the U.S. Department of Energy under contract ;Mode of access: Internet
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