By using a two-step solid-state reaction to synthesize the yellow-persistent GdAlGaO:Ce phosphor, both the luminescence and afterglow properties were greatly enhanced. Its internal quantum efficiency reaches as high as 81.9%, indicating its promising application in reducing the flicker effect in AC-LED-based white light systems.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1039/c7cc05041k | DOI Listing |
Chemistry
December 2024
Lodz University of Technology: Politechnika Lodzka, Faculty of Biotechnology and Food Sciences, POLAND.
A series of benzothieno[3,2-b]benzothiophene S-oxides has been efficiently synthesized via one- or two-step selective oxidation of benzothieno[3,2-b]benzothiophene (BTBT). These BTBT S-oxides form highly ordered structures that display optical anisotropy, are thermally stable up to temperatures above 210 oC, and do not show phase transitions. They exhibit long excited state lifetimes (0.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
December 2024
Department of Physics, Centre for the Physics of Materials, McGill University, Montreal, QC H3A OB8, Canada.
The formation of excited dimer states, so called excimers, is an important phenomenon in many organic molecular semiconductor solid state aggregates. In contrast to Frenkel exciton-polarons, an excimer is long-lived and energetically low-lying due to stabilization resulting from a substantial reorganization of the intermolecular geometry. Here, we show that ultrafast electron diffraction can follow the dynamics of solid-state excimer formation in polycrystalline thin films of a molecular semiconductor, revealing both the key reaction modes and the eventual structure of the emitting state.
View Article and Find Full Text PDFNat Commun
November 2024
Department of Physics and Astronomy, University of California, Irvine, CA, USA.
Oxide ceramic electrolytes (OCEs) have great potential for solid-state lithium metal (Li) battery applications because, in theory, their high elastic modulus provides better resistance to Li dendrite growth. However, in practice, OCEs can hardly survive critical current densities higher than 1 mA/cm. Key issues that contribute to the breakdown of OCEs include Li penetration promoted by grain boundaries (GBs), uncontrolled side reactions at electrode-OCE interfaces, and, equally importantly, defects evolution (e.
View Article and Find Full Text PDFDalton Trans
December 2024
Chair of Solid-State and Quantum Chemistry, Institute of Inorganic Chemistry, RWTH Aachen University, 52056 Aachen, Germany.
LiMnHf(NCN) and LiMnZr(NCN) were prepared solid-state metathesis reactions either a more exothermic direct reaction between LiNCN, MnCl and HfCl or a milder two-step reaction in which ternary LiZr(NCN) was first prepared and subsequently reacted with MnF. Their crystal structures were determined from powder X-ray diffraction data and found to crystallize isotypically in low-symmetry variants of the [NiAs]-type MNCN structure with 3̄1 symmetry and comprise corundum-like [(NCN)] layers ( = Hf, Zr) alternating with [LiMn(NCN)] layers. In-depth chemical bonding analysis was undertaken using LOBSTER to calculate the Löwdin charges which reveal significant differences in covalency between the two metal layers that is also reflected in the crystal orbital bond indices (COBI) of the metal-nitrogen bonds as well as the carbon-nitrogen bonds that show distinct single and triple bond character, which is also evident from infrared spectroscopy measurements.
View Article and Find Full Text PDFNat Commun
October 2024
School of Molecular Sciences, University of Western Australia, Crowley, Western Australia, Australia.
Molecules that can reversibly switch between electronic states under an external stimulus are of interest to numerous applications. Complexes of open shell metal ions with redox active ligands undergo valence tautomerism, resulting in magnetic, colour and structural switching, relevant to data storage and actuators. However, the precise structural changes occurring during valence tautomerism in the solid state are unclear due to the lack of atomic-resolution characterization.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!