We investigated the controlling mechanism of preferential orientation in polycrystalline silicon (poly-Si) on glass substrate by Al-induced crystallization using an in situ monitoring system and electron backscattered diffraction (EBSD) measurements. Poly-Si film with (111)-preferential orientation was obtained by the layer exchange of the initial amorphous silicon (a-Si)/Al/glass into Al/poly-Si/glass. Cross-sectional EBSD revealed that Al crystal grains are much smaller than those of Si, and randomly oriented without any epitaxial relationship between (111)-oriented Si despite the fact that (111)-oriented Si is believed to originate from epitaxial growth on -Al 2 O 3 /Al(111). This suggests that another mechanism such as minimization of surface energy affects the formation of (111)-oriented poly-Si. #
Ah igh-purity methylammonium lead iodide complex with intercalated dimethylformamide (DMF) molecules, CH 3 NH 3 PbI 3 ·DMF,i si ntroduced as an effective precursor material for fabricating high-quality solution-processed perovskite layers.S pin-coated films of the solvent-intercalated complex dissolved in pure dimethyl sulfoxide (DMSO) yielded thick, dense perovskite layers after thermal annealing.The low volatility of the pure DMSO solvent extended the allowable time for low-speed spin programs and considerably relaxed the precision needed for the antisolvent addition step.A no ptimized, reliable fabrication method was devised to take advantage of this extended process windowa nd resulted in highly consistent performance of perovskite solar cell devices, with up to 19.8 %p ower-conversion efficiency (PCE). The optimizedmethod was also used to fabricate a22.0 cm 2 ,eightcell module with 14.2 %P CE (active area) and 8.64 Voutput (1.08 V/cell).Hybrid organic-inorganic lead halide perovskites are promising materials for cost-effective printable photovoltaics. As ar esult of the enhanced purity of the reagents [1,2] and careful optimization of the perovskite layer fabrication process, conversion efficiencies have increased significantly since the first report on perovskite solar cells in 2009. [26] Thehighest certified power-conversion efficiency(PCE) now exceeds 23 %. [27,28] Forl arge-area devices,h owever, the certified PCE of as ubmodule still remains under 12 %. [28]
New chemotherapeutic agents with novel mechanisms of action are urgently required to combat the challenge imposed by the emergence of drug-resistant mycobacteria. In this study, a phenotypic whole-cell screen identified 5-nitro-1,10-phenanthroline (5NP) as a lead compound. 5NP-resistant isolates harbored mutations that were mapped to and were also resistant to the bicyclic nitroimidazole PA-824. Mechanistic studies confirmed that 5NP is activated in an F-dependent manner, resulting in the formation of 1,10-phenanthroline and 1,10-phenanthrolin-5-amine as major metabolites in bacteria. Interestingly, 5NP also killed naturally resistant intracellular bacteria by inducing autophagy in macrophages. Structure-activity relationship studies revealed the essentiality of the nitro group for activity, and an analog, 3-methyl-6-nitro-1,10-phenanthroline, that had improved activity and efficacy in mice compared with that of 5NP was designed. These findings demonstrate that, in addition to a direct mechanism of action against, 5NP also modulates the host machinery to kill intracellular pathogens.
CH 3 NH 3 PbI 3 (MAPbI 3) perovskite layers can be obtained by thermal annealing thin films of the intermediate dimethyl sulfoxide (DMSO) intercalated complex, MA 2 Pb 3 I 8 ¢2DMSO. In the present work, the formation, structure, and thermal transformation of the intermediate complex in both bulk and thin film form is examined in detail. The grain size and orientation of the intermediate crystallites in the solvent-intercalated thin film material is shown to directly influence the flatness of the annealed perovskite layer. Flat-lying orientation of the small needle-like intermediate crystallites is found to yield dense and flat perovskite layers. Optimized spin coating and annealing processes are developed for the formation and thermal conversion, respectively, of the intermediate film. Based on these methods, MAPbI 3 perovskite solar cells with high power conversion efficiency (maximum ³20.3%) were obtained with high reproducibility.
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