ZnO:B back reflector with high haze and low absorption enhanced triple-junction thin film Si solar modules

AbstractWe present our development of a ZnO:B back reflector (BR) with high haze and low absorption for highly efficient triple-junction thin film Si solar modules over a large area (1.1×1.3m2). We try to maximize light trapping by the evaluation of the use of transparent conducting oxide (TCO) and BR for high efficiency. It was verified that the configuration of SnO2:F front TCO and ZnO:B BR shows better optical properties than typical configurations for light trapping due to its high transparency at the front and high haze at the back. In addition, we noticed that the absorption of the BR has a strong influence on the solar modules. We obtained a superior ZnO:B BR with high haze and low absorption by controlling the doping gas ratio (B2H6/DEZ). As the doping gas ratio of ZnO:B BR decreases, the haze increases due to a rougher surface morphology, and the absorption decreases due to reduced free carrier absorption. The solar modules with a ZnO:B BR in a lower doping gas ratio show relatively higher Pmax for the same i-μc-Si layer thickness. This results from an increased Isc due to higher haze and lower absorption. In addition, the ZnO:B BR with a low doping gas ratio was found to be effective in reducing the i-μc-Si layer thickness because there are more chances for trapping the light at the i-μc-Si layer. We could reduce the i-μc-Si layer thickness by about 28% for the equivalent Pmax level by lowering the doping gas ratio. We successfully applied the ZnO:B BR with high haze and low absorption into a triple-junction thin film silicon solar cell and achieved a new record, improving on our previous world record

Correlation between pulsating auroras and chorus waves observed at Athabasca (L=4.4), Canada

第3回極域科学シンポジウム/第36回極域宙空圏シンポジウム 11月26日（月）、27日（火） 国立極地研究所 2階ラウン

Exosomes from Human Adipose Tissue-Derived Mesenchymal Stem Cells Promote Epidermal Barrier Repair by Inducing de Novo Synthesis of Ceramides in Atopic Dermatitis.

Atopic dermatitis (AD) is a multifactorial, heterogeneous disease associated with epidermal barrier disruption and intense systemic inflammation. Previously, we showed that exosomes derived from human adipose tissue-derived mesenchymal stem cells (ASC-exosomes) attenuate AD-like symptoms by reducing multiple inflammatory cytokine levels. Here, we investigated ASC-exosomes' effects on skin barrier restoration by analyzing protein and lipid contents. We found that subcutaneous injection of ASC-exosomes in an oxazolone-induced dermatitis model remarkably reduced trans-epidermal water loss, while enhancing stratum corneum (SC) hydration and markedly decreasing the levels of inflammatory cytokines such as IL-4, IL-5, IL-13, TNF-α, IFN-γ, IL-17, and TSLP, all in a dose-dependent manner. Interestingly, ASC-exosomes induced the production of ceramides and dihydroceramides. Electron microscopic analysis revealed enhanced epidermal lamellar bodies and formation of lamellar layer at the interface of the SC and stratum granulosum with ASC-exosomes treatment. Deep RNA sequencing analysis of skin lesions demonstrated that ASC-exosomes restores the expression of genes involved in skin barrier, lipid metabolism, cell cycle, and inflammatory response in the diseased area. Collectively, our results suggest that ASC-exosomes effectively restore epidermal barrier functions in AD by facilitating the de novo synthesis of ceramides, resulting in a promising cell-free therapeutic option for treating AD

An Analysis Of Discharge And Water Level Changes Due To Weir (In The Case Of The Waegwan And Nakdong Station In South Korea)

ABSTRACT Our country, Korea, lacks the per capita water endowment because of the high population density and geographical characteristics. Therefore, The 4 Rivers Project has been promoted since 2009. In order to control effectively drought or floods caused by abnormal climate and strong rainfall in summer, it was done and completed in 2013. The Nakdong River is the longest in the 4 Rivers Project, which it was conducted among the country\u27s major rivers, and a lot of hydraulic structures were installed. we selected Nakdong and Weagwan stations which are located in the Nakdong River. Because the change was smaller there with the inflow of tributaries flow than elsewhere. And many hydraulic structures were installed between Nakdong and Weagwan stations, which used T/M machine to collect real-time data. In this study, we compared and analyzed the flow change of real-time and water level data of prior to weir installation on May, June, July, 2009 and completion of weir installation on May, June, July , 2013. The original purpose of installing the weir is well-kept. After installation of Hydraulic structures(weir), the discharge difference between the Nakdong Station and Weagwan Station was reduced , and both of Nakdong and Weagwan stations are almost maintain a constant value of water level without being affected by rainfall. Also, we could confirm that the maximum water-level variation is decreased after installation of the weir. Based on this, we judged that hydrological effects on drought or floods due to abnormal weather were decreased by the time of weir installation. ACKNOWLEDGEMENT This research was supported by a grant(12-TI-C01) from Advanced Water Management Research Program funded by Ministry of Land, Infrastructure and Transport of Korean governmen

Effect of the Phosphorus Gettering on Si Heterojunction Solar Cells

To improve the efficiency of crystalline silicon solar cells, should be collected the excess carrier as much as possible. Therefore, minimizing the recombination both at the bulk and surface regions is important. Impurities make recombination sites and they are the major reason for recombination. Phosphorus (P) gettering was introduced to reduce metal impurities in the bulk region of Si wafers and then to improve the efficiency of Si heterojunction solar cells fabricated on the wafers. Resistivity of wafers was measured by a four-point probe method. Fill factor of solar cells was measured by a solar simulator. Saturation current and ideality factor were calculated from a dark current density-voltage graph. External quantum efficiency was analyzed to assess the effect of P gettering on the performance of solar cells. Minority bulk lifetime measured by microwave photoconductance decay increases from 368.3 to 660.8 mu s. Open-circuit voltage and short-circuit current density increase from 577 to 598 mV and 27.8 to 29.8mA/cm(2), respectively. The efficiency of solar cells increases from 11.9 to 13.4%. P gettering will be feasible to improve the efficiency of Si heterojunction solar cells fabricated on P-doped Si wafers.open1