The International Financial Cooperation - Recent Reforms

The current financial crisis demonstrated, once again, the need for strengthened international financial cooperation. This article discusses the features of the international financial architecture and recent changes focusing on the role of the Financial Stability Board (FSB). It briefly reviews the post-war BrettonWood arrangements and the changes that occurred after their establishment and recounts the genesis of the FSB and its role in promoting a coherent regulatory framework for a globally integrated financial syste

О методах расчета ?'-потенциала при наличии адсорбированных на электроде органических веществ

Проведено сравнение исходных посылок различных методов расчета ?'-потенциала и результатов расчета по этим методам для случая адсорбции на ртути ?-нафтола. Показано, что для адсорбирующихся веществ, меняющих ориентацию молекул относительно поверхности электрода лучшие результаты дает определение ?'-потенциала по сдвигу максимума электрокапиллярной кривой

Естественная радиоактивность кольчугинской серии отложений Ленинского геолого-экономического района Кузбасса

Рассматриваются на основании исследования 1435 образцов горных пород естественные радиоактивные свойства мелко- и крупнозернистого алевролитов и мелкозернистого песчаника, а также каменных углей. Отмечается различие по естественной радиоактивности между основными литологическими разностями пород, слагающих кольчугинскую серию. Естественная радиоактивность пород закономерно уменьшается от алевролитов к песчаникам и к углям. Угли по естественной радиоактивности резко отличаются от вмещающих пород

HIGH RATE SPUTTERING OF ZNO:AL FROM ROTATING CATHODES AS FRONT CONTACT IN SILICON THIN FILM SOLAR CELLS

ABSTRACT: Aluminium doped zinc oxide (ZnO:Al) thin films were deposited by mid-frequency magnetron sputtering method from rotatable dual magnetrons at different substrate temperatures, working pressure and discharge power on Corning glass substrates. The ceramic zinc oxide targets are doped with 0.5 wt% aluminium oxide. Highly transparent films with low resistivity below 4×10 -4 ·cm were obtained at deposition rates up to 110 nm·m/min. The ZnO:Al films were texture-etched in diluted hydrochloric acid before they were applied as front contacts in silicon thin-film solar cells. For films deposited at low deposition rate the etched films show a surface with regularly distributed large craters and a root mean square roughness of around 140 nm. Microcrystalline silicon solar cells with 8.5% conversion efficiency were prepared on these films. The high rate ZnO:Al films exhibit reduced light scattering after etching. Nevertheless a conversion efficiency of 7.5% was achieved on these substrates

High Deposition Rate Aluminium Doped Zinc Oxide Films with Highly Efficient Light Trapping for Silicon Thin Film Solar Cells

Abstract Aluminium doped zinc oxide films were deposited on glass substrates at high rates by reactive mid frequency sputtering. The in-line sputter system allows oxygen influx along the middle and sides of a dual cathode system. The effect of varying the oxygen flow from the sides on the electrical and optical properties together with the surface morphology after wet chemical etching was investigated. Increasing the amount of oxygen flow from the sides improved the resistivity profile of static prints and gave highly conductive and transparent films in dynamic deposition mode. The etched films developed rough surface textures with effective light scattering which could be controlled by the oxygen balance between the middle and sides. Optimally textured films were used as front contacts in 1cm2 single junction µc-Si:H solar cells yielding an initial efficiency of 8.4 %. The improvement in light trapping lead to short circuit densities higher than that of the reference solar cells

Chemical interaction at the buried silicon/zinc oxide thin-film solar cell interface as revealed by hard x-ray photoelectron spectroscopy

Hard X-ray photoelectron spectroscopy (HAXPES) is used to identify chemical interactions (such as elemental redistribution) at the buried silicon /aluminum-doped zinc oxide thin-film solar cell interface. Expanding our study of the interfacial oxidation of silicon upon its solid-phase crystallization (SPC), in which we found zinc oxide to be the source of oxygen, in this investigation we address chemical interaction processes involving zinc and aluminum. In particular, we observe an increase of zinc- and aluminum-related HAXPES signals after SPC of the deposited amorphous silicon thin films. Quantitative analysis suggests an elemental redistribution in the proximity of the silicon/aluminum-doped zinc oxide interface – more pronounced for aluminum than for zinc – as explanation. Based on these insights the complex chemical interface structure is discussed

Understanding an empirically optimized contact

The electronic structure of the interface between the boron-doped oxygenated amorphous silicon “window layer” (a-SiOx:H(B)) and aluminum-doped zinc oxide (ZnO:Al) was investigated using hard x-ray photoelectron spectroscopy and compared to that of the boron-doped microcrystalline silicon (μc- Si:H(B))/ZnO:Al interface. The corresponding valence band offsets have been determined to be (−2.87 ± 0.27) eV and (−3.37 ± 0.27) eV, respectively. A lower tunnel junction barrier height at the μc-Si:H(B)/ZnO:Al interface compared to that at the a-SiOx:H(B)/ZnO:Al interface is found and linked to the higher device performances in cells where a μc-Si:H(B) buffer between the a-Si:H p-i-n absorber stack and the ZnO:Al contact is employed

Light scattering and trapping in different thin film photovoltaic device

Light trapping in different thin film technologies is investigated in the context of the European integrated project ATHLET since it allows for thinner devices and thus for reduction of costs for absorber material preparation as well as for advanced multi-junction solar cells. In silicon technology, rough interfaces are typically introduced by roughening of substrates, transparent conducting oxides (TCOs) and/or reflectors at the back side to scatter the light into the absorber material. Well known rough TCOs, plasma-textured poly-Si as well as rough Cu(In,Ga)Se2 (CIGS) absorbers are used as source for light scattering in microcrystalline silicon solar cells and compared regarding their surface roughness. The results prove that CIGS and poly silicon solar cells provide efficient light scattering by the surface features of the rough absorber

Fabrication of surface-patterned ZnO thin films using sol-gel methods and nanoimprint lithography

Surface-patterned ZnO thin films were fabricated by direct imprinting on ZnO sol and subsequent annealing process. The polymer-based ZnO sols were deposited on various substrates for the nanoimprint lithography and converted to surface-patterned ZnO gel films during the thermal curing nanoimprint process. Finally, crystalline ZnO films were obtained by subsequent annealing of the patterned ZnO gel films. The optical characterization indicates that the surface patterning of ZnO thin films can lead to an enhanced transmittance. Large-scale ZnO thin films with different patterns can be fabricated by various easy-made ordered templates using this combination of sol-gel and nanoimprint lithography techniques.Comment: 17 pages, 5 figures; Published in Journal of Sol-Gel Science and Technology, 201