About the origin of low wafer performance and crystal defect generation on seed-cast growth of industrial mono-like silicon ingots

The era of the seed-cast grown monocrystalline-based silicon ingots is coming. Mono-like, pseudomono or quasimono wafers are product labels that can be nowadays found in the market, as a critical innovation for the photovoltaic industry. They integrate some of the most favorable features of the conventional silicon substrates for solar cells, so far, such as the high solar cell efficiency offered by the monocrystalline Czochralski-Si (Cz-Si) wafers and the lower cost, high productivity and full square-shape that characterize the well-known multicrystalline casting growth method. Nevertheless, this innovative crystal growth approach still faces a number of mass scale problems that need to be resolved, in order to gain a deep, 100% reliable and worldwide market: (i) extended defects formation during the growth process; (ii) optimization of the seed recycling; and (iii) parts of the ingots giving low solar cells performance, which directly affect the production costs and yield of this approach. Therefore, this paper presents a series of casting crystal growth experiments and characterization studies from ingots, wafers and cells manufactured in an industrial approach, showing the main sources of crystal defect formation, impurity enrichment and potential consequences at solar cell level. The previously mentioned technological drawbacks are directly addressed, proposing industrial actions to pave the way of this new wafer technology to high efficiency solar cells

Residual Strain and Electrical Activity of Defects in Multicrystalline Silicon Solar Cells

Producción CientíficaThe growth process by casting methods of multi-crystalline Si results in a crystalline material with, among other defects, a high density of dislocations and grain boundaries. Impurity incorporation and their gathering around grain boundaries and dislocations seem to be the main factor determining the electrical activity of those defects, which limit the minority carrier lifetime. In this work, we analyze multi-crystalline Si samples by combining etching processes to reveal the defects, Raman spectroscopy for strain measurements, and light beam induced current measurements for the localization of electrically active defects. In particular, we have explored the etching routes capable to reveal the main defects (grain boundaries and dislocation lines), while their electrical activity is studied by the light beam induced current technique. We further analyze the strain levels around these defects by Raman micro-spectroscopy, aiming to obtain a more general picture of the correlation between residual stress and electrical activity of the extended defects. The higher stress levels are observed around intra-grain defects associated with dislocation lines, rather than around the grain boundaries. On the other hand, the intra-grain defects are also observed to give dark light beam induced current contrast associated with a higher electrical activity of these defects as compared to the grain boundariesJunta de Castilla y León (programa de apoyo a proyectos de investigación – Ref. A166A11-2)Ministerio de Ciencia e innovación (IPT-420000-2010- -022 INNPACTO program

Mono-crystalline silicon wafers manufactured by casting methods: Optoelectronic, structural and solar cell study

1) Introduction 2) The Quasi-mono, pseudo-mono, mono-like ERA. 3) Manufacturing mono-cast ingots: COST (seed recycling) 4) Summary and findings 5) Current status at DCWafer

Myliobatis freminvillii, bullnose eagle ray

The Bullnose Eagle Ray (Myliobatis freminvillii) is a medium-sized (to 106 cm disc width) demersal coastal eagle ray that occurs in the Northwest, Western Central, and Southwest Atlantic Oceans from Massachussetts, USA to the Texas coast of the Gulf of Mexico and from Venezuela to Buenos Aires, Argentina and inhabits continental shelves from the surface to a depth of 122 m. Its is captured by artisanal longlines, gillnets, beach seines and also in industrial shrimp trawls. In the Northwest Atlantic, population trend data are available from a deep-water trawl survey in the northern Gulf of Mexico that reveal steep increases in abundance over 2002-2013. There are no known threats in the Northwest and Western Central Atlantic, but in the Southwest Atlantic artisanal fisheries are intense. Further, there are largely unmanaged commercial trawl and longline fisheries in this area. This inshore eagle ray is exposed to intense and often unmanaged fishing pressure throughout the Southwest Atlantic portion of its range, and it has no refuge at depth. Due to the level of exploitation by widespread artisanal fisheries which lack adequate management, it is suspected that this species has undergone a population reduction of >80% over the past three generation lengths (44 years) in the Atlantic South American part of its range, but is stable in the Northwest and Western Central Atlantic. Overall, based on its range, with almost all threats found in the Southwest Atlantic, and the suspected low productivity of the species, the Bullnose Eagle Ray is suspected to have undergone a population reduction of 30-49% in the past three generation lengths (44 years) due to levels of exploitation, and it is assessed as Vulnerable A2bd.Fil: Carlson, J.. National Marine Fisheries Service; Estados UnidosFil: Charvet, P.. Universidade Federal do Paraná; BrasilFil: Avalos, C.. Fundacion Mundo Azul; GuatemalaFil: Blanco Parra, M. P.. Universidad de Quintana Roo; MéxicoFil: Briones Bell lloch, A.. Direccion de Regulaciones Pesqueras y Ciencias; CubaFil: Cardeñosa, D.. Florida International University; Estados UnidosFil: Chiaramonte, Gustavo Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia". Estación Hidrobiológica de Puerto Quequén (sede Quequén); ArgentinaFil: Cuevas, J.M.. Wildlife Conservation Society; Estados UnidosFil: Derrick, D.. University Fraser Simon; CanadáFil: Espinoza, E.. Direccion Parque Nacional Galapagos; EcuadorFil: Mejía Falla, P. A.. Wildlife Conservation Society; Estados UnidosFil: Morales Saldaña, J. M.. Smithsonian Tropical Research Institute; PanamáFil: Motta, F.. Universidade Federal de Sao Paulo; BrasilFil: Naranjo Elizondo, B.. Universidad de Costa Rica; Costa RicaFil: Pacoureau, N.. University Fraser Simon; CanadáFil: Paesch, L.. Dirección Nacional de Recursos Acuáticos; UruguayFil: Perez Jiménez, J. C.. El Colegio de la Frontera del Sur; MéxicoFil: Rincon, G.. Universidade Federal Do Maranhao.; BrasilFil: Schneider, E. V. C.. Cape Eleuthera Institute; BahamasFil: Simpson, N. J.. Salvageblue; San Vicente y las GranadinasFil: Talwar, B. S.. Florida International University; Estados UnidosFil: Pollom, R.. University Fraser Simon; Canad

Myliobatis goodei, southern eagle ray

The Southern Eagle Ray (Myliobatis goodei) is a medium-sized (to at least 115 cm DW) coastal eagle ray that occurs in the Western Central and Southwest Atlantic Oceans from South Carolina and Florida, USA and Quintana Roo, Mexico to San Jorge Gulf, Santa Cruz, Argentina. It inhabits continental shelves from inshore to depths of 181 m. It is captured using artisanal longlines, gillnets, beach seines, and in industrial shrimp trawls. This species is inferred to be stable or increasing in the Western Central Atlantic, based on its similarity to the Bullnose Eagle Ray (Myliobatis freminvillei). In the Southwest Atlantic artisanal fisheries are intense, further there are largely unmanaged commercial trawl and longline fisheries in many areas. In Brazil, landings of eagle rays have been reduced by 60% over 2000?2012 in Santa Catarina State, and a reduction of 91% in Rio Grande do Sul since the 1980s. This inshore eagle ray has no refuge at depth and is exposed to intense and often unmanaged fishing pressure throughout the Atlantic South American portion of its range and there it is suspected that this species has undergone a population reduction of >80% over the past three generation lengths (44 years), but is stable in the Western Central Atlantic. Overall, based its range with the almost all threats found in the Southwest Atlantic, the suspected low productivity of the species, this species is suspected to have undergone a population reduction of 30 49% in three generation lengths (44 years) due to levels of exploitation, and it is assessed as Vulnerable A2d.Fil: Carlson, J.. National Marine Fisheries Service; Estados UnidosFil: Charvet, P.. Universidade Federal do Paraná; BrasilFil: Avalos Castillo, C.. Fundación Mundo Azul; GuatemalaFil: Blanco Parra, M. P.. Universidad de Quintana Roo; MéxicoFil: Briones Bell lloch, A.. Dirección de Regulaciones Pesqueras y Ciencias; CubaFil: Cardeñosa, D.. Florida International University; Estados UnidosFil: Chiaramonte, Gustavo Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia". Estación Hidrobiológica de Puerto Quequén (sede Quequén); ArgentinaFil: Cuevas, J.M.. Wildlife Conservation Society; Estados UnidosFil: Derrick, D.. University Fraser Simon; CanadáFil: Espinoza, E.. Galapagos National Park Directorate; EcuadorFil: Mejía Falla, P. A.. Wildlife Conservation Society; Estados UnidosFil: Morales Saldaña, J. M.. Smithsonian Tropical Research Institute; PanamáFil: Motta, F.. Universidade Federal Do Sao Paulo; BrasilFil: Naranjo Elizondo, B.. Universidad de Costa Rica; Costa RicaFil: Pacoureau, N.. University Fraser Simon; CanadáFil: Paesch, L.. Direccion Nacional de Recursos Acuaticos ; UruguayFil: Pérez Jiménez, J. C.. El Colegio de la Frontera del Sur; MéxicoFil: Rincon, G.. Universidade Federal Do Maranhao.; BrasilFil: Schneider, E. V. C.. Cape Eleuthera Institute; BahamasFil: Simpson, N. J.. Salvageblue; San Vicente y las GranadinasFil: Talwar, B. S.. Florida International University; Estados UnidosFil: Pollom, R.. University Fraser Simon; Canad

Measurement of χ c1 and χ c2 production with s√ = 7 TeV pp collisions at ATLAS

The prompt and non-prompt production cross-sections for the χ c1 and χ c2 charmonium states are measured in pp collisions at s√ = 7 TeV with the ATLAS detector at the LHC using 4.5 fb−1 of integrated luminosity. The χ c states are reconstructed through the radiative decay χ c → J/ψγ (with J/ψ → μ + μ −) where photons are reconstructed from γ → e + e − conversions. The production rate of the χ c2 state relative to the χ c1 state is measured for prompt and non-prompt χ c as a function of J/ψ transverse momentum. The prompt χ c cross-sections are combined with existing measurements of prompt J/ψ production to derive the fraction of prompt J/ψ produced in feed-down from χ c decays. The fractions of χ c1 and χ c2 produced in b-hadron decays are also measured

Single hadron response measurement and calorimeter jet energy scale uncertainty with the ATLAS detector at the LHC

The uncertainty on the calorimeter energy response to jets of particles is derived for the ATLAS experiment at the Large Hadron Collider (LHC). First, the calorimeter response to single isolated charged hadrons is measured and compared to the Monte Carlo simulation using proton-proton collisions at centre-of-mass energies of sqrt(s) = 900 GeV and 7 TeV collected during 2009 and 2010. Then, using the decay of K_s and Lambda particles, the calorimeter response to specific types of particles (positively and negatively charged pions, protons, and anti-protons) is measured and compared to the Monte Carlo predictions. Finally, the jet energy scale uncertainty is determined by propagating the response uncertainty for single charged and neutral particles to jets. The response uncertainty is 2-5% for central isolated hadrons and 1-3% for the final calorimeter jet energy scale.Comment: 24 pages plus author list (36 pages total), 23 figures, 1 table, submitted to European Physical Journal

Search for squarks and gluinos in events with isolated leptons, jets and missing transverse momentum at s√=8 TeV with the ATLAS detector

The results of a search for supersymmetry in final states containing at least one isolated lepton (electron or muon), jets and large missing transverse momentum with the ATLAS detector at the Large Hadron Collider are reported. The search is based on proton-proton collision data at a centre-of-mass energy s√=8 TeV collected in 2012, corresponding to an integrated luminosity of 20 fb−1. No significant excess above the Standard Model expectation is observed. Limits are set on supersymmetric particle masses for various supersymmetric models. Depending on the model, the search excludes gluino masses up to 1.32 TeV and squark masses up to 840 GeV. Limits are also set on the parameters of a minimal universal extra dimension model, excluding a compactification radius of 1/R c = 950 GeV for a cut-off scale times radius (ΛR c) of approximately 30

Measurements of fiducial and differential cross sections for Higgs boson production in the diphoton decay channel at s√=8 TeV with ATLAS

Measurements of fiducial and differential cross sections are presented for Higgs boson production in proton-proton collisions at a centre-of-mass energy of s√=8 TeV. The analysis is performed in the H → γγ decay channel using 20.3 fb−1 of data recorded by the ATLAS experiment at the CERN Large Hadron Collider. The signal is extracted using a fit to the diphoton invariant mass spectrum assuming that the width of the resonance is much smaller than the experimental resolution. The signal yields are corrected for the effects of detector inefficiency and resolution. The pp → H → γγ fiducial cross section is measured to be 43.2 ±9.4(stat.) − 2.9 + 3.2 (syst.) ±1.2(lumi)fb for a Higgs boson of mass 125.4GeV decaying to two isolated photons that have transverse momentum greater than 35% and 25% of the diphoton invariant mass and each with absolute pseudorapidity less than 2.37. Four additional fiducial cross sections and two cross-section limits are presented in phase space regions that test the theoretical modelling of different Higgs boson production mechanisms, or are sensitive to physics beyond the Standard Model. Differential cross sections are also presented, as a function of variables related to the diphoton kinematics and the jet activity produced in the Higgs boson events. The observed spectra are statistically limited but broadly in line with the theoretical expectations