A highly sensitive ratiometric optical thermometer based on a SrMgWO double perovskite doped with Dy exploiting thermally coupled and uncoupled levels.

The increasing demand for highly sensitive optical thermometers operating within a wide temperature range necessitates the development of new phosphors. In this work, the potential temperature sensing performance of a novel yellow-emitting phosphor, SrMgWO double perovskite, doped with varying concentrations of Dy was investigated for the first time. Increasing the concentration of Dy from 0% to 7% shifted the color of luminescence from blue to yellowish-orange within the CIE1931 color space.

Effect of A-Cation Radius on the Structure, Luminescence, and Temperature Sensing of Double Perovskites AMgWO Doped with Dy (A = Ca, Sr, Ba).

Herein, we report a case of AMgWO (A = Ca, Sr, Ba) doped with 2%Dy, 2%Li, in which the influences of the cation substitution are exhibited through the crystal structure, the charge transfer band (O-W), the emission spectrum, the color of the luminescence, and the luminescent decay time. The substitution of Ca and Sr ions for larger ions (Ba) led to the crystal structure alteration from cubic to monoclinic and tetragonal, respectively. These structure changes also lowered the crystallography symmetry site of Dy, tuned the color of the emitted light from the whitish to yellowish region, and caused a blue shift of the CTB.

Structure, Luminescence and Temperature Detection Capability of [C(NH)]M(HCOO) (M = Mg, Mn, Zn) Hybrid Organic-Inorganic Formate Perovskites Containing Cr Ions.

Metal-organic frameworks are of great interest to scientists from various fields. This group also includes organic-inorganic hybrids with a perovskite structure. Recently their structural, phonon, and luminescent properties have been paid much attention.

Effect of Ceramic Formation on the Emission of Eu and Nd Ions in Double Perovskites.

Herein, the structure, morphology, as well as optical properties of the powder and ceramic samples of BaMgWO are presented. Powder samples were obtained by high temperature solid-state reaction, while, for the ceramics, the SPS technique under 50-MPa pressure was applied. The morphology of the investigated samples showed some agglomeration and grains with a submicron size of 490-492 µm.

Exploration of the Temperature Sensing Ability of LaMgTiO:Er Double Perovskites Using Thermally Coupled and Uncoupled Energy Levels.

This work aimed to explore the temperature-sensing performance of LaMgTiO:Er double perovskites based on thermally coupled and uncoupled energy levels. Furthermore, the crystal structure, chemical composition, and morphology of the samples were investigated by powder X-ray diffraction, energy-dispersive X-ray spectroscopy, and scanning electron microscopy, respectively. The most intense luminescence was observed for the sample doped with 5% Er.

Improving Color Quality of Nanowire White Light-Emitting Diodes with Mn Doped Fluoride Nanosheets.

A two-dimensional nanostructured fluoride red-emitting phosphor with an excellent quantum yield of ~91% is studied for cost-effective and high-color quality nanowire white light-emitting diodes (WLEDs). KTiF:Mn phosphors are synthesized via an emulsification method using surfactants as sodium dodecyl sulphonate and oleic acid. The KTiF:Mn phosphors in ultra-thin and nanosheet crystals are observed via scanning electron microscopy and high-resolution transmission electron microscopy.

Temperature sensitivity modulation through changing the vanadium concentration in a LaMgTiO:V,Cr double perovskite optical thermometer.

To fulfil the requirements of operating at low temperature in a harsh environment, the investigation on optical thermometers plays an increasingly important role. In this work, the influence of vanadium concentration on the capability of temperature readout by La2MgTiO6:V5+,Cr3+ luminescent thermometers was investigated for the first time. The presence of V3+ and V5+ was verified by XPS and absorption measurements.

Deep red fluoride dots-in-nanoparticles for high color quality micro white light-emitting diodes.

In this study, a novel nanostructure of fluoride red emitting phosphor is synthesized via soft templates. KSiF:Mn nanocrystals in the range of 3-5 nm diameter are found inside the porous KSiF:Mn nanoparticle hosts, forming unique dots-in-nanoparticles (d-NPs) structures with controlled optical properties. The porous KSiF:Mn d-NPs exhibit a sharp and deep red emission with an excellent quantum yield of ∼95.

Synthesis, Structure, Morphology, and Luminescent Properties of BaMgWO: Eu Double Perovskite Obtained by a Novel Co-Precipitation Method.

Eu doped BaMgWO (BMW) double-perovskite was successfully synthesized for the first time by the co-precipitation method. The synthesis procedure, crystal structure, as well as morphology of obtained samples are presented. Domination of the D-F magnetic-dipole over forced electric-dipole transitions in the emission spectra indicates that Eu ions are located in the high symmetry site with inversion center.