126 research outputs found
Potential of interdigitated back contact silicon heterojunction solar cells for liquid phase crystallized silicon on glass with efficiency above 14
Liquid phase crystallization of silicon LPC Si on glass is a promising method to produce high quality multi crystalline Si films with macroscopic grains. In this study, we report on recent improvements of our interdigitated back contact silicon heterojunction contact system IBC SHJ , which enabled open circuit voltages as high as 661 mV and efficiencies up to 14.2 using a 13 m thin n type LPC Si absorbers on glass. The influence of the BSF width on the cell performance is investigated both experimentally and numerically. We combine 1D optical simulations using GenPro4 and 2D electrical simulations using Sentaurus TCAD to determine the optical and electrical loss mechanisms in order to estimate the potential of our current LPC Si absorbers. The simulations reveal an effective minority carrier diffusion length of 26 m and further demonstrate that a doping concentration of 4 1016 cm 3 and a back surface field width of 60 m are optimum values to further increase cell efficiencie
Silicon solar cells on glass with power conversion efficiency above 13 at thickness below 15 micrometer
Liquid phase crystallized silicon on glass with a thickness of 10 40 amp; 956;m has the potential to reduce material costs and the environmental impact of crystalline silicon solar cells. Recently, wafer quality open circuit voltages of over 650 mV and remarkable photocurrent densities of over 30 mA cm 2 have been demonstrated on this material, however, a low fill factor was limiting the performance. In this work we present our latest cell progress on 13 amp; 956;m thin poly crystalline silicon fabricated by the liquid phase crystallization directly on glass. The contact system uses passivated back side silicon hetero junctions, back side KOH texture for light trapping and interdigitated ITO Ag contacts. The fill factors are up to 74 and efficiencies are 13.2 under AM1.5 g for two different doping densities of 1 10 17 cm 3 and 2 10 16 cm 3 . The former is limited by bulk and interface recombination, leading to a reduced saturation current density, the latter by series resistance causing a lower fill factor. Both are additionally limited by electrical shading and losses at grain boundaries and dislocations. A small 1 0.1 cm 2 test structure circumvents limitations of the contact design reaching an efficiency of 15.9 clearly showing the potential of the technolog
Does the majority always know best? Young children's flexible trust in majority opinion
Copying the majority is generally an adaptive social learning strategy but the majority does not always know best. Previous work has demonstrated young children's selective uptake of information from a consensus over a lone dissenter. The current study examined children's flexibility in following the majority: do they overextend their reliance on this heuristic to situations where the dissenting individual has privileged knowledge and should be trusted instead? Four- to six- year-olds (N = 103) heard conflicting claims about the identity of hidden drawings from a majority and a dissenter in two between-subject conditions: in one, the dissenter had privileged knowledge over the majority (he drew the pictures); in the other he did not (they were drawn by an absent third party). Overall, children were less likely to trust the majority in the Privileged Dissenter condition. Moreover, 5- and 6- year-olds made majority-based inferences when the dissenter had no privileged knowledge but systematically endorsed the dissenter when he drew the pictures. The current findings suggest that by 5 years, children are able to make an epistemic-based judgment to decide whether or not to follow the majority rather than automatically following the most common view
Attentional learning helps language acquisition take shape for atypically developing children, not just children with Autism Spectrum Disorders
The shape bias-generalising labels to same shaped objects-has been linked to attentional learning or referential intent. We explore these origins in children with typical development (TD), autism spectrum disorders (ASD) and other developmental disorders (DD). In two conditions, a novel object was presented and either named or described. Children selected another from a shape, colour or texture match. TD children choose the shape match in both conditions, children with DD and 'high-verbal mental age' (VMA) children with ASD (language age > 4.6) did so in the name condition and 'low-VMA' children with ASD never showed the heuristic. Thus, the shape bias arises from attentional learning in atypically developing children and is delayed in ASD
Surface behavior of amphiphiles in aqueous solution: a comparison between different pentanol isomers
ESCRT-III-driven piecemeal micro-ER-phagy remodels the ER during recovery from ER stress
The endoplasmic reticulum (ER) produces about 40% of the nucleated cell’s proteome. ER size and content in molecular chaperones increase upon physiologic and pathologic stresses on activation of unfolded protein responses (UPR). On stress resolution, the mammalian ER is remodeled to pre-stress, physiologic size and function on activation of the LC3-binding activity of the translocon component SEC62. This elicits recov-ER- phagy, i.e., the delivery of the excess ER generated during the phase of stress to endolysosomes (EL) for clearance. Here, ultrastructural and genetic analyses reveal that recov-ER-phagy entails the LC3 lipidation machinery and proceeds via piecemeal micro- ER-phagy, where RAB7/LAMP1-positive EL directly engulf excess ER in processes that rely on the Endosomal Sorting Complex Required for Transport (ESCRT)-III component CHMP4B and the accessory AAA+ ATPase VPS4A. Thus, ESCRT-III-driven micro-ER- phagy emerges as a key catabolic pathway activated to remodel the mammalian ER on recovery from ER stress
EARLINET instrument intercomparison campaigns: overview on strategy and results
This paper introduces the recent European Aerosol Research Lidar Network (EARLINET) quality-assurance efforts at instrument level. Within two dedicated campaigns and five single-site intercomparison activities, 21 EARLINET systems from 18 EARLINET stations were intercompared between 2009 and 2013. A comprehensive strategy for campaign setup and data evaluation has been established. Eleven systems from nine EARLINET stations participated in the EARLINET Lidar Intercomparison 2009 (EARLI09). In this campaign, three reference systems were qualified which served as traveling standards thereafter. EARLINET systems from nine other stations have been compared against these reference systems since 2009. We present and discuss comparisons at signal and at product level from all campaigns for more than 100 individual measurement channels at the wavelengths of 355, 387, 532, and 607¿nm. It is shown that in most cases, a very good agreement of the compared systems with the respective reference is obtained. Mean signal deviations in predefined height ranges are typically below ±2¿%. Particle backscatter and extinction coefficients agree within ±2¿¿×¿¿10-4¿km-1¿sr-1 and ±¿0.01¿km-1, respectively, in most cases. For systems or channels that showed larger discrepancies, an in-depth analysis of deficiencies was performed and technical solutions and upgrades were proposed and realized. The intercomparisons have reinforced confidence in the EARLINET data quality and allowed us to draw conclusions on necessary system improvements for some instruments and to identify major challenges that need to be tackled in the future.Peer ReviewedPostprint (published version
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