Gadolinium-yttrium- aluminum-gallium garnets (GYAGG) doped and codoped with Eu, Tb, and Ce were manufactured as ceramics to develop long-wavelength phosphors for high-brightness white light sources based on cathodoluminescence (CL). The CL light yield (LY) of Tb-doped ceramics at high-intensity electron beam excitation is shown to be more than twice as high as that of the conventional phosphor YAG:Ce, whereas codoping with Eu to redshift the chromaticity results in reducing the LY approximately to the level of YAG:Ce. The LY might be substantially improved by using a mix of Tb- and Eu-doped GYGAG powders instead of a single codoped GYGAG to produce ceramic phosphor. The high LY is explained by favorable contribution of Gd sublattice in excitation transfer to activator ions. Chromaticity of phosphors GYGAG:Tb, Eu can be tuned in a wide range by varying the ratio of Tb to Eu concentration. They are radiation resistant and stabile in the temperature range from 300 to 450 K.
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http://dx.doi.org/10.1016/j.heliyon.2022.e10193 | DOI Listing |
Adv Sci (Weinh)
January 2025
Institute of Applied Materials, Helmholtz-Zentrum Berlin für Materialien und Energie, Hahn-Meitner-Platz 1, 14109, Berlin, Germany.
The phenomena occurring in a weld seam during advancement of a laser beam over a metallic component are still under dispute. The occurrence and evolution of porosity and the occasional blowout of melt need to be understood. Here, a recently developed X-ray tomoscopy setup is applied, providing one hundred 3D images per second to capture the temporal evolution of the melt pool in an AlSi9Cu3(Fe) die-casting while a laser beam advances.
View Article and Find Full Text PDFAdv Sci (Weinh)
January 2025
Department of Physics, University of Ulsan, Ulsan, 44610, Republic of Korea.
The anisotropic properties of materials profoundly influence their electronic, magnetic, optical, and mechanical behaviors and are critical for a wide range of applications. In this study, the anisotropic characteristics of Ni-based van der Waals materials, specifically NiTe and its alloy NiTeSe, utilizing a combination of comprehensive scanning tunneling microscopy (STM), angle-resolved photoemission spectroscopy (ARPES), and density functional theory (DFT) calculations, are explored. Unlike 1T-NiTe, which exhibits trigonal in-plane symmetry, the substitution of Te with Se in NiTe (resulting in the NiTeSe alloy) induces a pronounced in-plane anisotropy.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
Department of Electrical Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan.
Semiconducting transition metal dichalcogenides (TMDs) possess exceptional photoelectronic properties, rendering them excellent channel materials for phototransistors and holding great promise for future optoelectronics. However, the attainment of high-performance photodetection has been impeded by challenges pertaining to electrical contact. To surmount this obstacle, we introduce a phototransistor architecture, in which the WS channel is connected with an alternating WS-WSe strip superstructure, strategically positioned alongside the source and drain contact regions.
View Article and Find Full Text PDFAnal Chem
January 2025
Department of Cancer Biology and Molecular Medicine, Beckman Research Institute, City of Hope Comprehensive Cancer Center, Duarte, California 91010, United States.
Extracellular vesicles (EVs), membrane-encapsulated nanoparticles shed from all cells, are tightly involved in critical cellular functions. Moreover, EVs have recently emerged as exciting therapeutic modalities, delivery vectors, and biomarker sources. However, EVs are difficult to characterize, because they are typically small and heterogeneous in size, origin, and molecular content.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Department of Chemistry, University of California, Berkeley, California 94720, United States.
Switchable selectivity achieved by altering reaction conditions within the same photocatalytic system offers great advantages for sustainable chemical transformations and renewable energy conversion. In this study, we investigate an efficient photocatalytic methanol dehydrogenation with controlled selectivity by varying the concentration of nickel cocatalyst, using zinc indium sulfide nanocrystals as a semiconductor photocatalyst, which enables the production of either formaldehyde or ethylene glycol with high selectivity. Control experiments revealed that formaldehyde is initially generated and can either serve as a terminal product or intermediate in producing ethylene glycol, depending on the nickel concentration in the solution.
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