Synthesis and Optical Properties of Organic-Inorganic Hybrid [(18-Crown-6)K][MoOCl(HO)].

Crown ether anchored organic-inorganic hybrid halides have been recently reported as interesting luminescent materials in the visible region of electromagnetic spectrum. Is it possible to develop such crown ether anchored hybrid materials for near infrared emission? Motivated by this question, we designed a new hybrid material, namely, [(18-Crown-6)K][MoOCl(HO)]. 18-Crown-6 ether bound with K form the cationic part [(18-Crown-6)K].

Thermochemistry of Solid-State Formation, Structure, Optical, and Luminescent Properties of Complex Oxides EuMeO (Me-Mo, W), EuWO: A Combined Experimental and DFT Study.

Complex oxides EuMeO (Me-Mo, W), EuWO were obtained by a solid-phase reaction between binary oxides. The thermodynamic and kinetic mechanisms of the reaction processes were established using a variety of physical-chemical methods. All compounds obtained in this work crystallize in the low-symmetry monoclinic system, forming complex framework structures, which determine a set of very valuable physical-chemical properties.

Achieving Ultra-Broadband Sunlight-Like Emission in Single-Phase Phosphors: The Interplay of Structure and Luminescence.

The quest for artificial light sources mimicking sunlight has been a long-standing endeavor, particularly for applications in anticounterfeiting, agriculture, and color hue detection. Conventional sunlight simulators are often cost-prohibitive and bulky. Therefore, the development of a series of single-phase phosphors CaLiMgAl(PO):0.

Phase Transitions and Nonlinear Optical Property Modifications in BaGaSe.

Phase transitions can change the crystal structure and modify the physical properties of crystals. In this work, we investigate the phase transition behavior in BaGaSe, an important middle infrared (mid-IR) nonlinear optical (NLO) crystal, in the temperature range from room temperature to 1173 K. Interestingly, the BaGaSe crystal undergoes a reversible ferroelastic phase transition at = 528 K, resulting in the presence of a newly discovered phase (γ-phase) at the higher temperature.

Yellow-Orange Emission in Sb-Doped Hexakis(thiocarbamidium) Hexabromoindium(III) Tribromide.

A luminescent zero-dimensional organic-inorganic hybrid indium halide (TUH)[InSbBr]Br (TU = thiourea, 0 ≤ ≤ 0.0998) was synthesized via the solvothermal method. In structures, resolved by single-crystal X-ray diffraction, isolated distorted [InBr] and [SbBr] octahedra are linked to organic TUH cations by intermolecular N-H···Br and N-H···S hydrogen bonds.

Two-Dimensional Hybrid Perovskite with High-Sensitivity Optical Thermometry Sensors.

Optical thermometry has gained significant attention due to its remarkable sensitivity and noninvasive, rapid response to temperature changes. However, achieving both high absolute and relative temperature sensitivity in two-dimensional perovskites presents a substantial challenge. Here, we propose a novel approach to address this issue by designing and synthesizing a new narrow-band blue light-emitting two-dimensional perovskite named (CHNO)PbBr using a straightforward solution-based method.

Realizing Persistent Zero Area Compressibility over a Wide Pressure Range in Cu GeO by Microscopic Orthogonal-Braiding Strategy.

Zero area compressibility (ZAC) is an extremely rare mechanical response that exhibits an invariant two-dimensional size under hydrostatic pressure. All known ZAC materials are constructed from units in two dimensions as a whole. Here, we propose another strategy to obtain the ZAC by microscopically orthogonal-braiding one-dimensional zero compressibility strips.

Evolution of Structures and Optical Properties in a Series of Infrared Nonlinear Optical Crystals LiAgInSe (0 ≤ ≤ 1).

In this work, a number of new infrared nonlinear optical (NLO) crystals of LiAgInSe, in which the ratio of Li/Ag varies in a wide range from 0 to 1, are investigated. Structural analysis reveals that the space group of LiAgInSe evolved from 4̅2 in AgInSe to Pna2 in LiInSe as increases from low values (0, 0.2, 0.

Unexpected giant negative area compressibility in palladium diselenide.

Negative area compressibility (NAC) is a counterintuitive 'squeeze-expand' behavior in solids that is very rare but attractive due to possible pressure-response applications and coupling with rich physicochemical properties. Herein, NAC behavior is reported in palladium diselenide with a large magnitude and wide pressure range. We discover that, apart from the rigid flattening of layers that has been generally recognized, the unexpected giant NAC effect in PdSe largely comes from anomalous elongation of intralayer chemical bonds.

Negative Thermal Expansion in the Polymorphic Modification of Double Sulfate β-AEu(SO) (A-Rb, Cs).

New polymorphic modifications of double sulfates β-AEu(SO) (A-Rb, Cs) were obtained by the hydrothermal method, the structure of which differs significantly from the monoclinic modifications obtained earlier by solid-state methods. According to single-crystal diffraction data, it was found that the compounds crystallize in the orthorhombic system, space group , with parameters β-RbEu(SO): = 9.4667(4) Å, = 13.

Eu Doping Concentration-Induced Site-Selective Occupation and Photoluminescence Tuning in KSrScSiO:Eu Phosphor.

Regulation of Eu dopants in different cation sites of solid-state materials is of great significance for designing multicolor phosphors for light-emitting diodes (LEDs). Herein, we report the selective occupation of Eu for multiple cationic sites in KSrScSiO, and the tunable photoluminescence from blue to cyan is realized through Eu doping concentration-dependent crystal-site engineering. Eu preferably occupies the K and Sr sites in KSrScSiO at a low doping concentration, resulting in a 440 nm blue emission.

Structural, Spectroscopic, Electric and Magnetic Properties of New Trigonal KFeHf(MoO) Orthomolybdate.

A new multicationic structurally disordered KFeHf(MoO) crystal belonging to the molybdate family is synthesized by the two-stage solid state reaction method. The characterization of the electronic and vibrational properties of the KFeHf(MoO) was performed using density functional theory calculations, group theory, Raman and infrared spectroscopy. The vibrational spectra are dominated by vibrations of the MoO tetrahedra, while the lattice modes are observed in a low-wavenumber part of the spectra.

Single Crystals of EuScCuSe: Synthesis, Experimental and DFT Investigations.

EuScCuSe was synthesized from the elements for the first time by the method of cesium-iodide flux. The crystal belongs to the orthorhombic system () with the unit cell parameters = 3.9883(3) Å, = 13.

Modulation of Bi luminescence from broadband green to broadband deep red in LuWO by Gd doping and its applications in high color rendering index white LED and near-infrared LED.

Phosphors that exhibit tunable broadband emissions are highly desired in multi-functional LEDs, including pc-WLEDs and pc-NIR LEDs. In this work, broadband emissions were obtained and modulated in the unexpectedly wide spectral range of 517-609 nm for (LuGdBi)WO phosphors by tuning the Gd content ( = 0-0.99).

Sequential and Reversible Phase Transformations in Zero-Dimensional Organic-Inorganic Hybrid Sb-based Halides towards Multiple Emissions.

Zero-dimensional (0D) metal halides have drawn increasing attention due to the attractive structure dependent photoluminescence (PL) properties. Here, we report two new 0D organic-inorganic hybrid Sb-based halides, (MTP) SbBr Sb Br ⋅H O (MTP=Methyltriphenylphosphonium, crystal 1) and (MTP) SbBr (crystal 2), featuring a reversible structural phase transformation and tunable orange and red emissions upon dehydration and rehydration of H O molecules. Intriguingly, a subsequent heat treatment further enables the formation of glassy state (MTP) SbBr (glass 3) with near-infrared luminescence, moreover, a sequential reverse phase transformation from glass 3 to crystal 2 and 1 is triggered by acetonitrile and water vapor stepwise.

A highly selective and rapid solvatochromic material for amide solvent detection.

The detection of amide solvents is essential to human health due to their carcinogenicity. A simple, solvatochromic luminescent material is presented for quick and accurate detection of amides. The luminescence color variation from blue to yellow is ascribed to the amide-induced phase transformation from CsZnBr:Cu to CsBr:Cu/Cu.

Ligand Engineering Triggered Efficiency Tunable Emission in Zero-Dimensional Manganese Hybrids for White Light-Emitting Diodes.

Zero-dimensional (0D) hybrid manganese halides have emerged as promising platforms for the white light-emitting diodes (-LEDs) owing to their excellent optical properties. Necessary for researching on the structure-activity relationship of photoluminescence (PL), the novel manganese bromides (CHN)MnBr and (CHN)MnBr are reported by screening two ligands with similar atomic arrangements but various steric configurations. It is found that (CHN)MnBr with planar configuration tends to promote a stronger electron-phonon coupling, crystal filed effect and concentration-quenching effect than (CHN)MnBr with chair configuration, resulting in the broadband emission (FWHM = 63 nm) to peak at 539 nm with a large Stokes shift (70 nm) and a relatively low photoluminescence quantum yield (PLQY) (46.

sp to sp Hybridization Transformation in Ionic Crystals under Unprecedentedly Low Pressure.

Under cold pressure sp /sp -to-sp hybridization transformation has been exclusively observed in covalent or molecular crystals overwhelmingly above ≈10 GPa, and the approaches to lower the transition pressure are limited on external heat-treatment and/or catalyzers. Herein we demonstrate that, by internal-lattice stress-transfer from ionic to covalent groups, the transformation can be significantly prompted, as shown in a crystal of LiBO under 2.85 GPa for the first case in ionic crystals.

Anisotropic Thermal Expansion and Electronic Structure of LiInSe.

Optical quality cm-sized LiInSe crystals were grown using the Bridgman-Stockbarger method, starting from pure element reagents, under the conditions of a low temperature gradient of 5-6 degrees/cm and a slight melt overheating. The phase purity of the grown crystal was verified by the powder XRD analysis. The thermophysical characteristics of LiInSe were determined by the XRD measurements in the temperature range of 303-703 K and strong anisotropy of the thermal expansion coefficients was established.

High-Efficiency Continuous-Luminescence-Controllable Performance and Antithermal Quenching in Bi-Activated Phosphors.

Recently, Bi-activated phosphors have been widely researched for phosphor-converted light-emitting diode (pc-LED) applications. Herein, novel full-spectrum ABO:Bi (A = Gd, La; B = Sb, Nb) phosphors with a luminescence-tunable performance were achieved by a chemical substitution strategy. In the LaSbO host material, a new luminescent center was introduced, with Gd replacing La.

Exploration of the Crystal Structure and Thermal and Spectroscopic Properties of Monoclinic Praseodymium Sulfate Pr(SO).

Praseodymium sulfate was obtained by the precipitation method and the crystal structure was determined by Rietveld analysis. Pr(SO) is crystallized in the monoclinic structure, space group 2/, with cell parameters = 21.6052 (4), = 6.

Integration of negative, zero and positive linear thermal expansion makes borate optical crystals light transmission temperature-independent.

Negative and zero thermal expansion (NTE and ZTE) materials are widely adopted to eliminate the harmful effect from the "heat expansion and cool contraction" effect and frequently embrace novel fundamental physicochemical mechanisms. To date, the manipulation of NTE and ZTE materials has mainly been realized by chemical component regulation. Here, we propose another method by making use of the anisotropy of thermal expansion in noncubic single crystals, with maximal tunability from the integration of linear NTE, ZTE and positive thermal expansion (PTE).

Thermophysical properties of lithium thiogallate that are important for optical applications.

Lithium thiogallate LiGaS is one of the most common nonlinear crystals for mid-IR due to its extreme beam strength and wide transparency range; however, its thermophysical properties have not yet been practically studied. Large crystals of high optical quality are grown. DTA revealed features at 1224 K below melting point (1304 K) that are associated with the oxygen containing compounds of the LiGaO S type.

Highly efficient Fe-doped ABB'O (A = Sr, Ca; B, B' = In, Sb, Sn) broadband near-infrared-emitting phosphors for spectroscopic analysis.

Near-infrared (NIR)-emitting phosphor-converted light-emitting diodes have attracted widespread attention in various applications based on NIR spectroscopy. Except for typical Cr-activated NIR-emitting phosphors, next-generation Cr-free NIR-emitting phosphors with high efficiency and tunable optical properties are highly desired to enrich the types of NIR luminescent materials for different application fields. Here, we report the Fe-activated SrCa(InSb)SnO phosphors that exhibit unprecedented long-wavelength NIR emission.

Anisotropic thermal expansion and electronic transitions in the CoBO ludwigite.

The investigations of the crystal structure, magnetic and electronic properties of CoBO at high temperatures were carried out using powder X-ray diffraction, magnetic susceptibility, electrical resistivity, and thermopower measurements. The orthorhombic symmetry (Sp.gr.