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Mixtures of nonfullerene acceptors (NFAs) are prepared to fine‐tune bulk heterojunction (BHJ) thin‐film morphologies. The acceptor phase resulting from these mixtures has unique physical properties with excellent optoelectronic processes that dictate the output of organic photovoltaic (OPV) devices. Remarkable short‐circuit current densities (JSC) and fill factors (FFs) are achieved due to the formation of better crystalline fibrils that suppress geminate recombination, leading to improved charge transport with enhanced crystallinity and aligned cascading energy levels confirm efficient exciton diffusion and dissociation, yielding more effective exciton recycling. The decreased Urbach energy and suppressed energetic disorder account for the improvement in the open‐circuit voltage (VOC). A maximum power conversion efficiency of 17.86% is obtained, underscoring the importance of using specific material interactions to produce a suitable morphology and manage energy loss, resulting in ideal organic solar cell (OSC) devices. [ABSTRACT FROM AUTHOR]

Heterojunction device performance has strong dependence on its junction interface. ZnO deposition over GaN to achieve a heterojunction is challenging as it usually requires high temperature and vacuum processing. It is even more demanding to achieve a crystalline interface while making ZnO nanorod based heterojunction. Here we report simple solution process for epitaxial growth of ZnO nanorods over GaN. High resolution x-ray diffraction studies revealed highly crystalline c-axis oriented ZnO nanorod growth by a simple hydrothermal process. ZnO/GaN heterojunction device fabricated using hydrothermally synthesized ZnO nanorods showed superior performance compared to polycrystalline sputter deposited ZnO based heterojunction. [ABSTRACT FROM AUTHOR]

As-grown and Dy-doped CdS thin films containing concentrations of 1, 2, 3, 4 and 5 at.% Dy atom were prepared via chemical spray route on glass substrates. The constructed thin films were searched through analyzing their structural, morphological, optical and electrical features. X-ray diffraction (XRD) surveys showed that as-grown and Dy-doped CdS thin films had hexagonal structure and the preferential orientation was along (101) plane for as-grown, 1 and 2 at.% Dy-dopings. But further dopings (3 and 4 at.%) caused more random orientation, especially for the case of 5 at.%, the preferred orientation changed to (002) plane. The crystallite size progressively lessened from 39 to 27 nm with increasing Dy-doping. The existence of a close relation between grain shape and the preferential orientation appeared as compared to micrographs of scanning electron microscopy with XRD data. 5 at.% Dy-doped CdS thin films possessed the best transmittance (over 80%) among all the samples. Except for 2 at.% Dy-doped CdS sample, the other samples had almost a band gap of 2.45 eV. Photoluminescence results revealed that more stoichiometric thin films were formed after Dy-incorporations. The outcomes of the electrical investigation evidenced that the best sample was 1 at.% Dy-doped CdS thin films since the lowest resistivity (6.35 × 103 Ω cm) and highest carrier concentration (1.06 × 1014 cm−3) were obtained for this specimen. [ABSTRACT FROM AUTHOR]

In this paper, effect of emulsification processes on the properties of Pickering emulsions stabilized by organomontmorillonites (OMts) was studied. Results of micro-morphology and X-ray diffraction showed that the structure of OMt in emulsion depended on the emulsification processes and had an effect on the stability of emulsion. We propose a schematic diagram to reveal the relationship between emulsification processes-OMt laminates structure-stability of Pickering emulsion. In emulsion prepared by ultrasonic, OMt showed uniform dispersion, loose structure, and irregular crystalline. In emulsion prepared by vortex mixing method, OMt illustrated stacking and coagulation structure. In emulsion prepared by microwave method, OMt showed interacting structure and had a little interaction with oil/water interface, and thus the properties of emulsion prepared by microwave was weakly related to oil/water ratios. Emulsification processes had a profound effect on the structure of OMt and stability of Pickering emulsion, which can be used as a trigger to prepare emulsion for various applications. [ABSTRACT FROM AUTHOR]

A supramolecular complex was constructed by encapsulation of a 3O2 molecule inside an open-cage C60 derivative. Its single-crystal X-ray diffraction analysis revealed the presence of the 3O2 at the center of the fullerene cage. The CV measurements suggested that unprecedented dehydrogenation was promoted by the encapsulated 3O2 after two-electron reduction. The ESR measurements displayed the triplet character as well as the anisotropy of the 3O2. Additionally, the SQUID measurements also demonstrated the paramagnetic behavior above 3 K without an antiferromagnetic transition. Upon photoirradiation with visible light, three phosphorescent bands at the NIR region were observed, arising from the exited 1O2 generated by self-sensitization with the outer cage, whose lifetimes were not affected by the environments. These studies confirmed that the complex is a crystalline triplet system with incompatible 'high spin density' but 'small interspin interaction' properties. [ABSTRACT FROM AUTHOR]

The structural properties of nanoscale Ag, La(OH), CuS (covellite), AgS (acanthite), and ZnO hollow spheres, massive Ag nanoparticles and In-Ag core-shell nanoparticles with outer diameters between 200 and 400 Å, were investigated by X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), scanning transmission electron microscopy (STEM), dynamic light scattering (DLS), and differential sedimentation (DS). Lognormal size distributions of single-crystalline (quasi)spherical nanoparticles are found in our samples by DLS, STEM, DS, and HRTEM. The lattice parameters of the nanomaterials are determined by XRD line-position analysis, while the volume-averaged size and the microstrain are derived by the average-size and strain approximation in the integral breadth method. A new expression is presented in this work to derive the real average outer diameter $$ \bar{D} $$ of hollow spherical particles. The good agreement between $$ \bar{D} $$ and the corresponding diameter determined by DLS in the case of Ag and La(OH) hollow spheres demonstrates the validity of the approach. The same expression is applied to derive the average wall thickness of CuS and AgS hollow spheres as well as for the Ag shell thickness of In-Ag core-shell nanoparticles. [ABSTRACT FROM AUTHOR]

The paper discusses the wear resistance, friction coefficient, and structure of friction surfaces of submicron crystalline Y-TZP-AlO composite rubbed against a steel disk counterface at a pressure of 5 MPa in a range of sliding speeds from 1 to 20 m/sec. It is shown that, starting at 2 m/sec, the friction surface is subdivided by a crack network into separate regions within which local spalling occurs at the maximum wear rate and a sliding speed of 5 m/sec. X-ray diffraction reveals inversion (with respect to the initial state) of the peak intensities of the tetragonal phase with random crystalline grain orientation. The degree of this inversion increases with sliding speed. These results are discussed in terms of the effects exerted by the reorientation of martensite-free deformation twins in the tetragonal phase and the formation of a quasi-liquid film on the wear resistance of Y-TZP-AlO. [ABSTRACT FROM AUTHOR]

By analyzing with X-ray diffraction and FT-IR spectroscopy, the main effective factors among common culture conditions on crystallinity index and I fraction of cellulose produced by Gluconacetobacter xylinus were examined with Plackett-Burman design experiment. Varying pH value in the medium by adjusting the composition of citrate buffer or by adding HCl/NaOH solution indicates it is the content of citrate buffer rather than its function of pH buffering that gives the influence on crystallinity. Further experiment reveals that Na concentration of 0.174 mol/l in medium with citrate buffer added would decrease the crystallinity index significantly. Comparison of carbon sources shows that fructose leads to a higher crystallinity index than glucose, which suggests a relationship between crystallinity and production speed of bacterial cellulose affected by carbon sources. An interesting phenomenon was that a longer period of cultivation would decrease the crystallinity of bacterial cellulose. The reason is assumed to be the dense network of cellulose formed by bacterial cells that restrict the motion of themselves as the incubation period extends. Though the effect of inoculum age is still unclear, the influence on crystallinity of bacterial cellulose caused by variation of some ordinary culture conditions can be drawn out from data of this work. [ABSTRACT FROM AUTHOR]

The article presents research which examined the use of high-resolution X-ray diffraction analysis in determining the effect of dopants on the crystalline perfection of ferroelectric glycine phosphite single crystals. The researchers selected dopants in various categories including rare-earth metals, transition metals and amino acids. They also assessed the concentration of dopants based on their crystallization characteristics during the growth process.

A general and facile approach for tailoring the multicolor output and shapes of lanthanide-ion doped fluoride upconversion nanoparticles (UCNPs) within a given composition is presented. By adjusting the temperature and time in the thermolysis procedure, the color output and shapes of NaYF4:20%Yb, 2%Er UCNPs can be readily manipulated. The nanoparticles were characterized through the use of transmission electron microscopy (TEM), powder X-ray diffraction (XRD) and upconversion luminescence spectroscopy. It is shown that the relative intensities of green emissions gradually increased with the rise of temperature and prolongation of growth time under excitation of 980 nm, which resulted in multicolor output of NaYF4:20%Yb, 2%Er UCNPs. Simultaneously, the shapes for UCNPs can also be controlled. TEM images, estimated micro-stress by Williamson–Hall methodology and a series of control experiments and analyses reveal that crystallinity is mainly responsible for the multicolor output of UCNPs. Based on the above method, the tailoring of color output is also successfully realized in Ho3+and Tm3+ions. It is expected that this method may be used to tune the physical properties of other nanoparticles, and these multicolored UCNPs are promising for applications in multiplexed bioimaging, biodetection, display, other optical technologies, etc. [ABSTRACT FROM AUTHOR]

The article presents a study which investigates the structure of N-(5-ethyl-[1,3,4]-thiadiazole-2-yl)-toluenesulfonamide compound. The study used X-ray powder diffraction (XRPD) data analysis, direct-space methods, and Carbon (C) cross-polarization magic angle-spinning (CP/MAS) spectrum analysis to determine the structure of the compound. Results showed that C atoms in the compound contains only one molecule in its asymmetric unit and is not a mixture of different form of crystalline elements.

The article presents a study on the crystal structure of M2As2O7 diarsenates, a transition metal which is considered as a variant of thortveitite structure. The study used differential scanning calorimetry (DSC), single-crystal X-ray diffraction, and X-ray powder diffraction to analyze its structure. It concludes that the incommensurability of ∝2-Cr2P2O7 and ∝-Zn2As2O7 structures is due to the interplay between metal oxide sequences in diarsenates atoms and X2O7 structure.

Removal of arsenate (As(V)) from aqueous solution using both nanocrystalline and coprecipitated Mg/Al layered double hydroxides (LDHs) was examined under different sorption/desorption conditions. The surface area, pore volume, and pore size of the nanocrystalline LDH were significantly higher than those of the coprecipitated LDH, thus resulting in a higher As(V) sorption maximum than the coprecipitated LDH. The calculated activation energy (Ea) value was 24.7 kJ/mol, suggesting the occurrence of anion exchange process for As(V) removal by the nanocrystalline LDH. The predominance of anion exchange process was further supported by the investigation of ionic strength effect, and XRD and FTIR analyses. The effect of aqueous matrix on As(V) sorption by the nanocrystalline LDH was found to increase in the order of nitrate < silica < sulfate < carbonate < phosphate. Regeneration study showed that a secondary sorption mechanism might occur concurrently for the As(V) sorption by nanocrystalline LDH besides the predominant anion exchange process. Prospects and challenges for practical application of the nanocrystalline LDH were also discussed in the latter part of this study. [ABSTRACT FROM AUTHOR]

Nowadays, hard coatings based on transition metal nitrides are extensively used for materials protection and particularly to improve the lifetime and performance of various cutting and forming tools. Practically, hard coatings need to be deposited on different kinds of substrate materials in different application areas. The physical properties, such as hardness, of the substrate may have evident influence on the properties and performance of the hard coatings. In this work, different kinds of hard coatings, including TiN, CrN, TiAlN, and CrAlN, were deposited by a lateral rotating cathode arc technique on two kinds of steel substrates with different hardness. The composition, crystalline structure, mechanical and tribological properties of the as-deposited hard coatings were systematically analyzed by energy dispersive analysis of X-rays, X-ray diffraction, nanoindentation, pin-on-disc tribometer, Rockwell indentation, and scratch test, respectively. The influence of substrate hardness on the properties of the hard coatings was investigated. It was found that the substrate hardness has little influence on the crystalline structure, nano-hardness, and tribological properties (friction coefficient and wear rate). However, it showed a significant effect of the toughness and adhesion of the hard coatings. It can be concluded that hard coatings need to be supported by hard substrates. [ABSTRACT FROM AUTHOR]

Novel bulk glassy samples of the pseudoternary chalcohalide Ge–S–AgI system have been prepared. Glasses have been obtained by monotemperature synthesis in evacuated ampoules and standard melt-quenching technique. The glass-forming region in the system determined by X-ray diffraction is situated in the S-rich region on the Ge–S side (S/Ge = 1.2, 1.5, 2 and 3) with AgI content up to 20 mol.%. Some physicochemical properties of the amorphous materials and their compositional dependence have been investigated. In addition, the theoretical average coordination number (Z), the total constraints per atom (Nco), the radial (Na) and axial (Nb) strength of the bonds have been calculated and related to the experimental results. [ABSTRACT FROM AUTHOR]

'In situ' wide angle (WAXS) and small angle X-ray scattering (SAXS) studies were carried out to characterize the structural changes occurring during the conversion of a polyamic acid into the polyimide in the presence of fullerene, C60. The variations in crystallinity, long period, and the SAXS invariant of the samples are discussed in the light of the various temperature ranges studied. The conversion of the polyamic acid into the polyimide is analyzed according to the different structural steps. Results reveal that C60 affects the degree of order of the composite in the molecular direction, giving rise to slightly smaller crystals than those found in pure polyamic acid. The difference in the SAXS data between the pure PAA and the composite are discussed through the interaction of C60 molecules with the polyamic acid, which seems to hinder the imidization reaction up to 185°C. [ABSTRACT FROM AUTHOR]

The effect of heat treatment on the structure, hardness, and electrical resistivity of the crystalline Sn 100- x In x ( x ?=?10?wt.%) solder alloy is studied. The structures of as-casted and heat-treated alloys have been investigated by means of a X-ray diffraction technique. Using X-ray analysis a crystalline ß-Sn and an In phase are detected. The amount of the crystalline phases increases upon increasing the annealing temperature. It is found that the fracture is delayed from 8.6?kg/mm 2 at 50?s and 100?g at room temperature to 4?kg/mm 2 at 90?s and 100?g at 423?K. Differential thermal analysis was used to investigate the melting characteristics of the alloy (m.p. ~214 ° C). The resistivity is also determined for samples thermally and non-thermally treated. [ABSTRACT FROM AUTHOR]

The correlation between the vicinal properties of SrTiO[sub 3] (001) substrates and the twinning in YBa[sub 2]Cu[sub 3]O[sub 7-x] thin films grown by pulsed-laser deposition is studied using x-ray diffraction with reciprocal space mapping. The vicinal properties, i.e., angle and in-plane orientation, play a significant role in the anisotropic strain starting at the interface between substrate surface and film, and affect the twin behavior of YBa[sub 2]Cu[sub 3]O[sub 7-x]. On substrates having an [110] in-plane orientation of the step edges, a completely preferred twin pair is observed if the vicinal angle is increased to 0.60°. Whereas on substrates having their step edges oriented along one of the crystallographic axis, the films exhibit a detwinning as the vicinal angle increases. For α=1.10° a maximum detwinned, i.e., monocrystalline film is obtained. At this angle, the diffusion length of YBa[sub 2]Cu[sub 3]O[sub 7-x] during the growth matches the terrace length of SrTiO[sub 3]. Up to this specific angle, the films are grown perpendicular to the optical instead of the crystallographic surface. © 2003 American Institute of Physics. [ABSTRACT FROM AUTHOR]

4H-polytype AlN has been grown on a 4H-SiC substrate with the (1120) face via plasma-assisted molecular-beam epitaxy. The microscopic structure of the AlN/4H-SiC interface was examined using high-resolution transmission electron microscopy, and the polytype replication of the 4H structure from the 4H-SiC(1120) substrate was evidently confirmed. The x-ray rocking curve of (1120) diffraction for the single crystalline 4H-AlN epilayer exhibited a very small linewidth of 90 arc sec, suggesting noticeably small tilting around the [1120] direction. The excellent crystalline quality is probably owing to the polytype matching between the 4H-AlN epilayer and the 4H-SiC substrate, which resulted in remarkable reduction of defects at the interface. © 2003 American Institute of Physics. [ABSTRACT FROM AUTHOR]