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Effects of 2-Amino-4,6-Dimethoxypyrimidine on PVDF/KI/I2-Based Solid Polymer Electrolytes for Dye-Sensitized Solar Cell Application
摘要： In this work, we have investigated the effects of 2-amino-4,6-dimethoxypyrimidine on polyvinylidene fluoride/potassium iodide/iodine (PVDF/KI/I2) in dye-sensitized solar cells (DSSC). Different weight ratios (0%, 10%, 20%, 30%, 40% and 50%) of 2-amino-4,6-dimethoxypyrimidine-doped PVDF/KI/I2-based solid polymer electrolytes (SPEs) were prepared by solution-casting method. The prepared 2-amino-4,6-dimethoxypyrimidine-doped PVDF/KI/I2-based SPEs were characterized by powder x-ray diffraction (PXRD) analysis, AC impedance analysis and scanning electron microscopy (SEM) analysis. The crystallinity of 2-amino-4,6-dimethoxypyrimidine-doped PVDF/KI/I2-based SPEs was confirmed by PXRD measurement. The ionic conductivity of 2-amino-4,6-dimethoxypyrimidine-doped PVDF/KI/I2-based SPEs was calculated using AC impedance analysis. The ionic conductivity values of different weight ratios (0%, 10%, 20%, 30%, 40% and 50%) of 2-amino-4,6-dimethoxypyrimidine-doped PVDF/KI/I2-based SPEs are 5.50 × 10?6 S cm?1, 1.74 × 10?5 S cm?1, 4.91 × 10?5 S cm?1, 2.04 × 10?5 S cm?1, 1.58 × 10?5 S cm?1 and 1.04 × 10?5 S cm?1, respectively. Ionic conductivity studies revealed that the 20% 2-amino-4,6-dimethoxypyrimidine-doped PVDF/KI/I2-based SPE showed the highest ionic conductivity value. The SEM images show the surface morphology of 2-amino-4,6-dimethoxypyrimidine-doped PVDF/KI/I2-based SPEs. The power conversion efficiency (PCE) of DSSCs utilizing different weight ratios (0%, 10%, 20%, 30%, 40% and 50%) of 2-amino-4,6-dimethoxypyrimidine-doped PVDF/KI/I2-based SPEs are 1.4%, 2.0%, 2.5%, 2.3%, 1.9% and 1.6%, respectively. These results revealed that the DSSC using 20% 2-amino-4,6-dimethoxypyrimidine-doped PVDF/KI/I2-based SPE exhibited the highest PCE.
关键词： crystalline nature,Powder x-ray diffraction,ionic conductivity,2-amino-4,6-dimethoxypyrimidine,solid polymer electrolyte
更新于2025-09-23 15:21:01
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Optical Characterization of the Photonic Ball as a Structurally Colored Pigment
摘要： A photonic ball is a spherical colloidal crystal. Because it can exhibit vivid structural colors, many attempts have been made to apply it as a structurally colored pigment. However, the optical properties of the photonic ball are complicated because di?erent crystal planes can be involved in the coloration mechanism, depending on the size of the constituent colloidal particles. In this paper, we report a comparative study of photonic balls consisting of silica particles with sizes ranging from 220 to 500 nm. We ?rst analyze the re?ectance spectra acquired in a nearly backscattering geometry and con?rm that Bragg di?raction from di?erent crystal planes causes several spectral peaks. Second, the angular dependence of re?ection is experimentally characterized and theoretically analyzed with appropriate models. These analyses and a comparison with a planar colloidal crystal reveal that the spherical shape plays an essential role in the minor iridescence of photonic balls. We ?nally discuss a method to enhance color saturation by incorporating small light-absorbing particles. We also discuss the iridescence of the photonic ball under directional and ambient illumination conditions.
关键词： structural coloration,photonic ball,iridescence,colloidal crystal,Bragg diffraction
更新于2025-09-23 15:21:01
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Reference Module in Chemistry, Molecular Sciences and Chemical Engineering || SPECTROPHOTOMETRY/Diode Array ☆
摘要： Diode array spectrometry represents a particular approach for characterizing the result of the interaction between electromagnetic radiation and the sample, based on simultaneous measurement of light intensity over small spectral intervals having equal width. This is achieved through the following sequential stages, as schematically shown in Figs. 1 and 2D: a. interaction between the polychromatic beam and the sample; b. spatial dispersion of the transmitted (eventually reflected or emitted) radiation according to wavelength on multiple channels of equal widths, by means of a fixed optical element; c. imaging the dispersed radiation in a focal plane; and d. (quasi)simultaneous sampling of the dispersed radiation interval using photosensitive detectors, precisely positioned in the focal plane.
关键词： photodiode principle,Diode array spectrometry,concave diffraction gratings,spectrophotometry,instrumentation
更新于2025-09-23 15:21:01
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Small fatigue crack growth behavior of Ti-6Al-4V produced via selective laser melting: In situ characterization of a 3D crack tip interactions with defects
摘要： Small fatigue crack growth (SFCG) behavior is examined for additively manufactured Ti-6Al-4V specimens with optimal and trial build conditions (representing an increased degree of defects) through a combination of in situ tomography and in situ energy dispersive X-ray diffraction. The results showed slower crack growth rates for the SFCG samples compared to the long cracks (which was not expected). In the case of the trial conditions, the increased levels of porosity deterred crack growth by blunting the crack, as evident by the in situ tomography characterization.
关键词： In situ tomography,Porosity,Energy dispersive X-ray diffraction,Process build conditions,Additive manufacturing
更新于2025-09-23 15:21:01
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Luminescent-center tuning for Ba6Ca3YAlSi6O24:Ce3+, Na+ orthosilicate phosphors
摘要： Ce3+ ion-doped Ba6Ca3YAlSi6O24 phosphors with a charge-compensating Na+ ion were prepared using a solid-state reaction. Ba6Ca3YAlSi6O24 was structurally characterized using synchrotron X-ray powder diffraction. The emission wavelengths of Ce3+ in different Ba2+ and Ca2+ sites with the distortion index of polyhedrons in the host lattice were calculated. The photoluminescence excitation and emission spectra of the Ce3+-activated phosphors were site-selectively monitored; furthermore, the emission quenching as a function of Ce3+ content in the Ba6-2xCexNaxCa3YAlSi6O24 and Ba6Ca3-2xCexNaxYAlSi6O24 (x = 0.01–0.4) was clearly distinguished at relatively high concentrations of the activator. The Gaussian components of the phosphors were exploited by using the Ce3+ ion sites in the host lattice; in addition, the one and two luminescent centers for the Ba6-2xCexNaxCa3YAlSi6O24 and Ba6Ca3-2xCexNaxYAlSi6O24 phosphors, respectively, were identified. The sites of the luminescent centers for the calculated Ba6Ca3-2xCexNaxYAlSi6O24 composition was selectively tuned as the (BaCa)9-2xCexNaxYAlSi6O24 lattice structure.
关键词： orthosilicate,photoluminescence,X-ray diffraction,luminescent center
更新于2025-09-23 15:21:01
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Characterization of Lattice Parameters Gradient of Cu(In1-xGax)Se2 Absorbing Layer in Thin-Film Solar Cell by Glancing Incidence X-Ray Diffraction Technique
摘要： In or Ga gradients in the Cu(In1-xGax)Se2 (CIGS) absorbing layer lead to change the lattice parameters of the absorbing layer, giving rise to the bandgap grading in the absorbing layer which is directly associated with the degree of absorbing ability of the CIGS solar cell. We tried to characterize the depth profile of the lattice parameters of the CIGS absorbing layer using a glancing incidence X-ray diffraction (GIXRD) technique, and then allows to determine the In or Ga gradients in the CIGS absorbing layer, and to investigate the bandgap grading of the CIGS absorbing layer. When the glancing incident angle increased from 0.50 to 5.00°, the a and c lattice parameters of the CIGS absorbing layer gradually decreased from 5.7776(3) to 5.6905(2) ?, and 11.3917(3) to 11.2114(2) ?, respectively. The depth profile of the lattice parameters as a function of the incident angle was consistent with vertical variation in the composition of In or Ga with depth in the absorbing layer. The variation of the lattice parameters was due to the difference between the ionic radius of In and Ga co-occupying at the same crystallographic site. According to the results of the depth profile of the refined parameters using GIXRD data, the bandgap of the CIGS absorber layer was graded over a range of 1.222 to 1.532 eV. This approach nondestructively guess the bandgap depth profile through the refinement of the lattice parameters using GIXRD data on the assumption that the changes of the lattice parameters or unit-cell volume follow a good approximation to Vegard’s law.
关键词： Vegard’s law,Cu(In1-xGax)Se2 absorbing layer,Depth profile,Bandgap grading,Glancing incidence X-ray diffraction technique
更新于2025-09-23 15:21:01
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Focusing properties of spirally polarized sinh Gaussian beam
摘要： The tight focusing properties of spirally polarized sinh-Gaussian beam is investigated numerically by vector diffraction theory. Results show that the optical intensity in focal region of spirally polarized sinh Gaussian beam can be altered considerably by the beam order, relative waist width and the spiral parameter that indicates the polarization spiral degree of the spirally polarized sinh Gaussian beam. Many novel focal patterns including flattop profile, focal hole axially separated focal spots and focal spot with long focal depth are evolved considerably for the suitable beam parameters. We expect such a tunable focal patterns are useful for optical manipulation of micro particles.
关键词： Vector diffraction theory,spirally polarized sinh Gaussian beam,Focusing property
更新于2025-09-23 15:21:01
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Determination of 60° polarization nanodomains in a relaxor-based ferroelectric single crystal
摘要： Here, we report a determination of monoclinic nanodomains in PMN-xPT with x ? 31%PT by using scanning convergent beam electron diffraction (SCBED). We show the presence of 60 6 a degree nanodomains with Cm-like symmetry as well as signi?cant variations (a) in local polarization directions across lengths of (cid:3)10 nm. The principle of our technique is general and can be applied for the determination of polarization domains in other ferroelectric materials of different symmetry. VC 2015 AIP Publishing LLC. [http://dx.doi.org/10.1063/1.4932955]
关键词： ferroelectric materials,scanning convergent beam electron diffraction,monoclinic nanodomains,PMN-xPT,SCBED
更新于2025-09-23 15:21:01
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Ultrathin films of L1 <sub/>0</sub> -MnAl on GaAs (001): A hard magnetic MnAl layer onto a soft Mn-Ga-As-Al interface
摘要： Ferromagnetic MnAl (L10-MnAl phase) ultrathin films with thickness varying from 1 to 5 nm have been epitaxially grown on a GaAs (001) substrate. A coercivity above 8 kOe has been obtained with no need of a buffer layer by tuning the sample preparation and the growth parameters. Surface and interface analysis carried out by in situ characterization techniques (x-ray photoelectron spectroscopy and low energy electron diffraction), available in the molecular beam epitaxy chamber, has shown the formation of a ferromagnetic interface consisting of Mn-Ga-As-Al, which contribution competes with the MnAl alloyed film. The appearance of this interface provides important information to understand the growth mechanism of MnAl-based films reported in the literature.
关键词： x-ray photoelectron spectroscopy,ferromagnetic,GaAs,molecular beam epitaxy,low energy electron diffraction,ultrathin films,L10-MnAl
更新于2025-09-23 15:21:01
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57Fe M?ssbauer and XRD studies on β-FeSi2 prepared by high energy mechanical attrition
摘要： The evolution of different phases of Fe-Si binary system on milling elemental Fe and Si has been carried out in argon atmosphere at 1000 rpm using the hardened tungsten carbide powders has been studied by x-ray diffractometry and 57Fe M?ssbauer spectroscopy. The milling medium. The sizes of both Fe and Si are found to be less than 50 nm on milling the mixture for 50 min. Metallic α-FeSi2 formation takes place at this stage due to enhanced reactivity caused by reduction in particle size. The semiconducting β-FeSi2 phase along with ε-FeSi and a metastable Fe-Si solid solution are found to be formed on annealing the milled product at 500 °C. A clean semiconducting β-FeSi2 phase forms on milling Fe and Si for 50 minute followed by annealing at 800 °C for 2 hrs.
关键词： M?ssbauer spectroscopy,X-ray diffraction,semiconducting β-FeSi2
更新于2025-09-23 15:21:01