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811.
The performance of organic photovoltaic devices based upon bulk heterojunction blends of donor and acceptor materials has been shown to be highly dependent on the thin film microstructure. In this tutorial review, we discuss the factors responsible for influencing blend microstructure and how these affect device performance. In particular we discuss how various molecular design approaches can affect the thin film morphology of both the donor and acceptor components, as well as their blend microstructure. We further examine the influence of polymer molecular weight and blend composition upon device performance, and discuss how a variety of processing techniques can be used to control the blend microstructure, leading to improvements in solar cell efficiencies. 相似文献
812.
We describe a novel, cost effective and simple technique for the manufacture of high sensitivity absorption cells for microfluidic analytical systems. The cells are made from tinted polymethyl methacrylate (PMMA) in which microfluidic channels are fabricated. Two windows (typically 250 μm thick, resulting in little optical power loss) are formed at either end of the channel through which light is coupled. Unwanted stray light from the emitter passes through a greater thickness of the tinted substrate (typically the length of the cell) and is preferentially absorbed. In effect, this creates a pin-hole configuration over the length of the absorption cell, providing improved performances (sensitivity, S/N ratios, baseline noise and limit of detection) when used as an absorption cell compared to clear substrates. The method is used to achieve a LOD of 20 nM with a colourimetric iron assay and a LOD of 0.22 milli-absorption units with a pH assay. 相似文献
813.
Norman JA Perez M Kim MS Lei X Ivanov S Derecskei-Kovacs A Matz L Buchanan I Rheingold AL 《Inorganic chemistry》2011,50(24):12396-12398
We report the synthesis, characterization, and experimental density function theory-derived properties of new volatile strontium and barium imidazolate complexes, which under atomic layer deposition conditions using ozone as a reagent can deposit crystalline strontium oxide at 375 °C. 相似文献
814.
Sarah L. Masters Iain D. Mackie Derek A. Wann Heather E. Robertson David W. H. Rankin Simon Parsons 《Structural chemistry》2011,22(2):279-285
The molecular structures of 1-Br-4-F-C6H4 and 1-Cl-4-F-C6H4 have been studied in the gas phase using gas electron diffraction (GED) and ab initio methods. The structure of 1-Cl,4-F-C6H4 in the crystalline phase has also been studied, but whilst the gaseous structures were found to possess C
2v symmetry, the solid-state structure was found to be quite distorted, with three molecules in the asymmetric unit. These fragments
only possess C
s symmetry in the plane of the molecules, as opposed to the C
2v symmetry observed in the gas phase. The bonding motifs within the solid-state structure are very unusual and unexpected,
with quite different C–F bond lengths for the three moieties, and are a result of weak hydrogen-halogen interactions within
the structure. 相似文献
815.
Matthew Abernathy Gregory Harry Jonathan Newport Hannah Fair Maya Kinley-Hanlon Samuel Hickey Isaac Jiffar Andri Gretarsson Steve Penn Riccardo Bassiri Eric Gustafson Iain Martin Sheila Rowan Jim Hough 《Physics letters. A》2018,382(33):2282-2288
We report on the mechanical loss from bulk and shear stresses in thin film, ion beam deposited, titania-doped tantala. The numerical values of these mechanical losses are necessary to fully calculate the Brownian thermal noise in precision optical cavities, including interferometric gravitational wave detectors like LIGO. We found the values from measuring the normal mode mechanical quality factors, Q's, in the frequency range of about 2000-10,000 Hz, of silica disks coated with titania-doped tantala coupled with calculating the elastic energy in shear and bulk stresses in the coating using a finite element model. We fit the results to both a frequency independent and frequency dependent model and find , with a frequency independent model and , with a frequency dependent (linear) model. The ratio of these values suggest that modest improvement in the coating thermal noise may be possible in future gravitational wave detector optics made with titania-doped tantala as the high index coating material by optimizing the coating design to take advantage of the two different mechanical loss angles. 相似文献
816.
Mads Sondrup Møller Dr. Victor Petrunin Prof. Susanne Mossin Prof. Vickie McKee Prof. Christine J. McKenzie 《欧洲无机化学杂志》2023,26(27):e202300235
Reactions of chemisorbed reagents inside the crystalline molecular solid state are rare but offer unexploited methods for selective solvent-free chemical synthesis. Here we show that the greenhouse gas precursor, nitric oxide (NO) is chemisorbed by crystals of the hexafluorophosphate salts of complexes containing dicobalt sites. On NO sorption a cascade of reactions results in the in-crystal synthesis of nitrite and other gaseous NOx. Recrystallization enabled structural elucidation of the mixed valent {[(bpbp)Co2(μ-(η1-O : η1-N)-ONO)]2(bdc)}4+ (bpbp=2,6-bis(N,N-bis(2-pyridylmethyl)aminomethyl)-4-tert-butylphenolato, bdc=1,4-benzenedicarboxylato) cation. Overlapping signals in the solid-state EPR spectra confirm the CoIICoIII oxidation state and the presence of NO2 trapped inside the unrecrystallised solid products (br. g=4, triplet g=2 (340 mT), A(N)=73 MHz), despite three cycles of vacuum and N2 flushing. Consistently, νN−O bands appear in the Raman and IR spectra that are due to the coordinated nitrate and the trapped NO2 that were synthesized in-crystal. The latter is expelled by heating the solid to 160 °C or by recrystallization. Dimetallic cooperativity is proposed for the NO transformations in these rare examples of selective, chemisorptive substrate reactions in the solid-state. 相似文献
817.