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91.
Investigation of fill factor losses on 20.2% efficient n‐type mono‐like silicon solar cells with laser contact opening 下载免费PDF全文
Alexander Frey Josh Engelhardt Gabriel Micard Giso Hahn Barbara Terheiden 《固体物理学:研究快报》2016,10(2):143-147
Large area (243.36 cm2) back‐junction passivated emitter, rear totally diffused (PERT) solar cells with laser contact opening (LCO) on n‐type mono‐like crystalline Si with efficiencies of 20.2% are presented. Boron emitters with high electrical quality (implied open circuit voltage iVOC up to 700 mV) are formed during a co‐diffusion step using SiOx:B layers. Increasing the rear metal contact coverage, we observed a decrease in fill factor (FF) instead of the expected increase due to the decrease of the back side series resistance. We show that it can be attributed to recombination centers (RCs) in the space charge region underneath the contact spots inducing an increasing second diode contribution. The presented empirical model for the RCs implemented in Synopsys Sentaurus TCAD allows for a successful reproduction of the FF, pseudo FF and VOC behaviour with contact coverage. According to this model, the RCs induced by laser ablation and subsequently evaporation of Al have a shallow exponential distribution with a characteristic length of LT = 0.2 µm and an effective surface density of N *T0 = 25 cm–1. (© 2016 WILEY‐VCH Verlag GmbH &Co. KGaA, Weinheim) 相似文献
92.
Li Q Gray KE Zheng H Claus H Rosenkranz S Ancona SN Osborn R Mitchell JF Chen Y Lynn JW 《Physical review letters》2007,98(16):167201
Contrary to conventional wisdom, our purified La 2-2x Sr 1+2x Mn2O7 crystals exhibit CE-type orbital and charge order as the low-temperature ground state for a hole doping level h=0.5. For small deviations from h=0.5, the high-temperature CE phase is replaced at low temperatures by an A-type antiferromagnet without coexistence. Larger deviations result in a lack of CE order at any temperature. Thus, small inhomogeneities in cation or oxygen composition could explain why others commonly see this reentrance with coexistence. 相似文献
93.
Baudat Emilie Gautier Céline Fichet Pascal Destrel Eric Colin Christèle Giuliani Margaux Lambrot Gabriel 《Journal of Radioanalytical and Nuclear Chemistry》2021,328(2):637-650
Journal of Radioanalytical and Nuclear Chemistry - 90Sr radiochemical method using nitric acid for Sr and Ca separation was optimized using design of experiments methodology. Nitric acid... 相似文献
94.
Homogeneous and unimolecular gas‐phase thermal decomposition kinetics of methyl benzoylformate: experimental and theoretical study 下载免费PDF全文
Yeljair Monascal Alexis Maldonado José R. Mora Tania Córdova Gabriel Chuchani 《Journal of Physical Organic Chemistry》2015,28(1):40-46
The kinetics of the gas‐phase thermal decomposition of the α‐ketoester methyl benzoylformate was carried out in a static system with reaction vessel deactivated with allyl bromide, and in the presence of the free radical inhibitor propene. The rate coefficients were determined over the temperature range of 440–481 °C and pressures from 32 to 80 Torr. The reaction was found to be homogenous, unimolecular and obey a first‐order rate law. The products are methyl benzoate and CO. The temperature dependence of the rate coefficient gives the following Arrhenius parameters: log10 k (s?1) = 13.56 ± 0.31 and Ea (kJ mol?1) = 232.6 ± 4.4. Theoretical calculations of the kinetic and thermodynamic parameters are in good agreement with the experimental values using PBE1PBE/6‐311++g(d,p). A theoretical Arrhenius plot was constructed at this level of theory, and the good agreement with the experimental Arrhenius plot suggests that this model of transition state may describe reasonably the elimination process. These results suggest a concerted non‐synchronous semi‐polar three‐membered cyclic transition state type of mechanism. The most advanced coordinate is the bond breaking Cδ+‐‐‐δ‐OCH3 with an evolution of 66.7%, implying this as the limiting factor of the elimination process. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
95.
Back Cover: Exploring Excited‐State Tunability in Luminescent Tris‐cyclometalated Platinum(IV) Complexes: Synthesis of Heteroleptic Derivatives and Computational Calculations (Chem. Eur. J. 52/2014) 下载免费PDF全文
96.
Stereospecific Formal [3+2] Dipolar Cycloaddition of Cyclopropanes with Nitrosoarenes: An Approach to Isoxazolidines 下载免费PDF全文
Shyamal Chakrabarty Dr. Indranil Chatterjee Birgit Wibbeling Dr. Constantin Gabriel Daniliuc Prof. Dr. Armido Studer 《Angewandte Chemie (International ed. in English)》2014,53(23):5964-5968
The MgBr2‐catalyzed formal [3+2] cycloaddition of donor–acceptor activated cyclopropanes with nitrosoarenes offers a novel approach to various structurally diverse isoxazolidines. The reactions, which are experimentally easy to conduct, occur with complete stereospecificity and perfect control of regioselectivity. Product isoxazolidines can be readily transformed into α‐amino lactones by reductive or decarboxylative N? O cleavage and subsequent lactonisation, and the N‐aryl bond cleavage is also possible under oxidative conditions. 相似文献
97.
Inside Back Cover: Molecular Salt Effects in the Gas Phase: Tuning the Kinetic Basicity of [HCCLiCl]− and [HCCMgCl2]− by LiCl and MgCl2 (Angew. Chem. Int. Ed. 41/2014) 下载免费PDF全文
98.
99.
Jérémy Vuilleumier Geoffrey Gaulier Raphaël De Matos Yannick Mugnier Gabriel Campargue Jean-Pierre Wolf Luigi Bonacina Sandrine Gerber-Lemaire 《Helvetica chimica acta》2020,103(1):e1900251
While chemotherapy is one of the most used treatments in oncology, the systemic administration of chemotherapeutics generally results in undesired damages to healthy tissues and cells, side effects such as severe nausea and leukopenia, and reduced efficacy due to multidrug resistance and poor target accessibility. The limitations of conventional chemotherapy formulation have prompted the development of alternative nanomaterials-based strategies to achieve targeted and stimuli sensitive payload delivery to reach optimal local drug concentration at tumor sites. In this study, the anticancer drug chlorambucil (Clb) was conjugated to the surface of silica coated lithium niobate (LNO) harmonic nanoparticles (HNPs) using a photocaging tether based on coumarin-4-yl methyl derivative. Upon laser pulsed femtosecond irradiation at 790 nm, the second harmonic emission from the metal oxide core induced the efficient release of Clb, with concomitant contribution from the nonlinear absorption of the coumarin (CM)-based moiety. 相似文献
100.
Jingxuan Ren Songfeng Han Ashley R. Proctor Danielle E. Desa Gabriel A. Ramirez Vincent Ralph D. Ching-Roa Joseph B. Majeski Irfaan A. Dar Nathaniel E. Barber Amanda M. Forti Danielle S.W. Benoit Regine Choe 《Photochemistry and photobiology》2020,96(2):380-387
Noninvasive monitoring of vascularization can potentially diagnose impaired bone healing earlier than current radiographic methods. In this study, a noncontact diffuse correlation tomography (DCT) technique was employed to measure longitudinal blood flow changes during bone healing in a murine femoral fracture model. The three-dimensional distribution of the relative blood flow was quantified from one day pre-fracture to 48 days post-fracture. For three mice, frequent DCT measurements were performed every other day for one week after fracture, and then weekly thereafter. A decrease in blood flow was observed in the bone fracture region at one day post-fracture, followed by a monotonic increase in blood flow beyond the pre-injury baseline until five to seven days post-fracture. For the remaining 12 mice, only weekly DCT measurements were performed. Data collected on a weekly basis show the blood flow for most mice was elevated above baseline during the first two post-fracture weeks, followed by a subsequent decrease. Torsional strength of the excised femurs was measured for all 15 mice after 7 weeks of healing. A metric based on the early blood flow changes shows a statistically significant difference between the high strength group and the low strength group. 相似文献