Boosting Red Luminescence of Mn in Tantalum Heptafluoride Based on an Ab Initio-Facilitated Sensitizer and Hydrophobic Surface Modification.

A narrow-band red-light component is critical to establish high color rendition and a wide color gamut of phosphor-converted white-light-emitting diodes (pc-WLEDs). In this sense, Mn-doped KSiF fluoride is the most successful material that has been commercialized. As with KSiF:Mn phosphors, Mn-doped tantalum heptafluoride (KTaF:Mn) fulfills a similar luminescence behavior and has been brought in a promising narrow-band red phosphor.

Temperature sensing of SrYGeO:Bi,Sm garnet phosphors with tunable sensitivity.

In this study, a novel temperature-sensitive material, SrYGeO:Bi,Sm phosphor, was successfully synthesized by a solid-state reaction method. Under 376 nm light excitation, the as-prepared phosphor presents both blue emissions of Bi and orange red emissions of Sm due to energy transfer from Bi to Sm. Owing to the significant difference in thermal quenching properties and the distinguishable emission between Bi and Sm ions, the temperature sensing performance of the prepared phosphor was evaluated by measuring the fluorescence intensity ratio (FIR) of Sm Bi.

Enlarging Sensitivity of Fluorescence Intensity Ratio-Type Thermometers by the Interruption of the Energy Transfer from a Sensitizer to an Activator.

The occurrence of energy transfer (ET) would enhance the luminescence of the activator but sacrifice that of the sensitizer. However, the novel Sm-doped CaTbSnAlO (CTSAO) phosphor reported here seems to be an exception. In the series of CTSAO:Sm phosphors investigated, something unexpected occurs; the activator, Sm, did not gain any energy compensation from the sensitizer, Tb, when temperature increases.

Crystal-field induced tuning of luminescence properties of NaGaAlF:Cr phosphors with good thermal stability for NIR LEDs.

Cr-Activated broadband near-infrared (NIR) luminescence materials are attracting much attention as next-generation smart NIR light sources that are widely used in night vision, bioimaging, medical treatment, and many other fields. Herein, a series of NaGaAlF:Cr NIR phosphors with broadband emission and tunable luminescence properties were designed and prepared. The luminescence intensity, peak position and full width at half maximum (FWHM) of the materials can be controlled by adjusting the crystal field strength.

Sensitization of Mn luminescence efficient energy transfer to suit the application of high color rendering WLEDs.

Developing novel luminescent materials with ideal properties is an endless project, urged by growing requirements of advances in energy saving, healthy lighting and environmental friendliness. Herein, a series of ScCaOBO:Ce,Mn phosphors with excellent luminescence properties were synthesized by the high temperature solid state method. X-ray diffraction was applied to analyse the phase composition of the obtained phosphors.

Disorder-Induced Broadband Near-Infrared Persistent and Photostimulated Luminescence in MgSnO:Cr.

Materials with near-infrared (NIR) persistent luminescence (PersL) and NIR-to-NIR photostimulated luminescence (PSL) properties are attractive platforms for photonic energy harvesting and release. In this work, we develop MgSnO:Cr as a broadband NIR PersL and NIR-to-NIR PSL material (luminescence maxima at ∼800 nm) and reveal the origin of the PersL and PSL properties. The material has an inverse spinel structure with the Mg and Sn disorder at the Wyckoff 16d site based on the Rietveld refinement.

Lead-Free Perovskite Narrow-Bandgap Oxide Semiconductors of Rare-Earth Manganates.

Tremendous success has been achieved in photovoltaic (PV) applications, but PV-generated electricity still cannot compete with traditional power in terms of price. Chemically stable and nontoxic all-oxide solar cells made from earth-abundant resources fulfill the requirements for low-cost manufacturing under ambient conditions and thus are promising as the next-generation approach to solar cells. However, the main obstacles to developing all-oxide solar cells are the spectral absorbers.

Reduced Local Symmetry in Lithium Compound LiSrSiO Distinguished by an Eu Spectroscopy Probe.

Research on lithium compounds has attracted much attention nowadays. However, to elucidate the precise structure of lithium compounds is a challenge, especially when considering the small ions that may be transferred between the interstitial voids. Here, the discovery of reduced local symmetry (symmetry breaking) in small domains of LiSrSiO is reported by employing Eu as a spectroscopic probe, for which X-ray, neutron, and electron diffraction have confirmed the average long-range structure with the space group 321.

Novel optical temperature sensor based on emission in Pr doped ferroelectric BaSrTiO.

Optical temperature sensing based on the variation of the fluorescence intensity ratio of rare-earth materials has become appealing due to its multiple superiorities over electrical temperature sensing. However, confined by the largest energy separation of two thermally linked levels of rare earth ions, the highest sensitivity of such temperature sensing is essentially smaller than 2878/ , as reported previously from diverse systems. In this work, we demonstrate that ultrahigh-sensitive temperature sensing can be achieved from Pr-doped (BaSr)TiO based on the intensity ratio of the D-H emission to the P-H emission.

Luminescence and Energy Transfer between Ce and Pr in BaYSiO under VUV-vis and X-ray Excitation.

A detailed investigation on photoluminescence properties and energy transfer (ET) dynamics of Ce, Pr-doped BaYSiO is provided along with the potential X-ray excited luminescence application. The luminescence properties of Pr are studied in VUV-UV-vis spectral range at low temperature, and the spectral profiles of PrP and D emission lines are determined using time-resolved emission spectra. Upon 230 nm excitation, the electron population from Pr 4f5d state to its 4f excited state is discussed in detail.

The Influence Mechanism of Halogen Ion on the Temperature Quenching Performance of Sr2SiO4:Eu Phosphors.

The luminescent properties of Sr2SiO4:Eu phosphors synthesized with and without flux have been investigated. With the co-dopation of NH4CI, the luminescent intensity of Sr2SiO4:Eu is increased and the temperature quenching property is improved. The effect of NH4Cl is analyzed not only from the crystallinity of the Sr2SiO4 crystal but also the band structure of Sr2SiO4 host, which is calculated by density functional method with the local density approximation.

Intense red light emission of Eu3+-doped LiGd(PO3)4 for mercury-free lamps and plasma display panels application.

In order to obtain a suitable red phosphor for mercury-free lamps and plasma display panels (PDPs), samples of trivalent europium-activated polyphosphate LiGd(PO(3))(4):Eu(3+) (LGP:Eu(3+)) were prepared by a solid-state reaction technique at high temperature. The vacuum ultraviolet (VUV)-visible spectroscopic properties were investigated. Because the phosphor LiGd(1-x)Eu(x)(PO(3))(4) for x = 0.