Pulsed Electric Discharge in Active Metallic Grains for Water Purification Processes

Chemical reactions in electric metal pulse dispersion in the aqueous solutions of inorganic substance (НSiO[3]{–}, Ni{2+}, Н[2]AsO[4]{–}, Mn{2+}, Cr[2]O[7]{2–}) were determined through IR spectroscopy, X-ray phase, chemical, kinetic, and thermodynamic analyses. Under such conditions, both reduction and oxidation reactions occur, as well as, locally initiated by heating, hydrolysis and exchange reactions without changing the oxidation rate of the dissolved substance itself. Reduction and oxidation of dissolved substances is determined by the generation and activation of high dispersed Fe in an electric discharge. Physical and chemical processes which take place under the action of pulse electric discharges upon the layer of metallic grains in salt solution, containing НSiO[3]{–}, Ni{2+}, Н[2]AsO[4]{–}, Mn{2+}, Cr[2]O[7]{2–} ions were determined on the basis of product composition, obtained experimentally and the thermodynamic data. It was shown, that PED discharge in heterogeneous mediums can be used for waste and natural water purification

Improved amorphous/crystalline silicon interface passivation by hydrogen plasma treatment

Silicon heterojunction solar cells have high open-circuit voltages thanks to excellent passivation of the wafer surfaces by thin intrinsic amorphous silicon (a-Si:H) layers deposited by plasma-enhanced chemical vapor deposition. We show a dramatic improvement in passivation when H2 plasma treatments are used during film deposition. Although the bulk of the a-Si:H layers is slightly more disordered after H2 treatment, the hydrogenation of the wafer/film interface is nevertheless improved with as-deposited layers. Employing H2 treatments, 4 cm2 heterojunction solar cells were produced with industry-compatible processes, yielding open-circuit voltages up to 725 mV and aperture area efficiencies up to 21. © 2011 American Institute of Physics