InCl-Assisted Surface Defects Restoring to Enhance Lead-Free CsZrCl Nanocrystals for X-Ray Imaging and Blue LED Applications.

As one type of recent emerging lead-free perovskites, CsZrCl nanocrystals are widely concerned, benefiting from the eminent designability, high X-ray cutoff efficiency, and favorable stability. Improving the luminescence performance of CsZrCl nanocrystals has great importance to cater for practical applications. In view of the surface defects frequently formed by the liquid phase method, the particle morphology and surface quality of this material are expected to be regulated if certain intervention is made in the synthesis process.

Anti-thermal quenching phosphors based on the new phosphate host CaIn(PO).

To enhance the working quality of WLEDs, considerable efforts have been made to upgrade the thermal quenching resistance of existing phosphors or design new anti-thermal quenching (ATQ) phosphors. Developing a new phosphate matrix material with special structural features has great importance for the fabrication of ATQ phosphors. By phase relationship and composition analysis, we have prepared a novel compound CaIn(PO) (CIP).

Environment-Dependent Eu-Activated BaCaK(PO) toward White-Light Emission by Chemical Cosubstitution of the (BO) Anion Group.

Investigating the phosphors doped with single activators in a single component to realize white-light emission is urgently desired for phosphor-converted white-light-emitting diodes. In this work, on the basis of the chemical unit cosubstitution strategy, the new borophosphate phosphors BaCaK(PO)(BO):0.02Eu with a mixed anion group were prepared.

Dependence of Luminous Performance on Eu Site Occupation in SrIn(PO): The Effect of the Local Environment.

The photoluminescence behavior of luminescent materials with rare earth (RE) ions as a luminescence center not only depends on the element type and chemical valence of RE ions but also on their concentration and occupation in the matrix, sometimes including the interaction of the matrix and RE ions or between different RE ions. Herein, special SrIn(PO) phosphate, assembled by monolayer [SrO] and bilayer [InPO] consisting of InO units and PO groups, was selected as the host material, and different cation positions (Sr and In) were substituted by Eu. The structure refinement in combination with Judd-Ofelt theory has shed light on the differences of the Eu coordination environment in SrIn(PO).

Daylight-White-Emitting and Abnormal Thermal Antiquenching Phosphors Based on a Layered Host SrIn(PO).

Single-phase white-emission phosphors possess a judicious usage potential in phosphor-converted white-light-emitting diodes (WLEDs). Recently, numerous efforts have been made toward the development of new patterns of white-emitting phosphors that achieve excellent quantum yield, superior thermal stability, and applaudable cost effectiveness of WLEDs. Finding suitable single-component white phosphor hosts to provide an ideal local environment for activators remains urgent.

The Non-Concentration-Quenching Phosphor CaEuBO for WLED Application.

Commercial white LED devices usually suffer from a high color temperature and poor color rendering. Developing a new, efficient, and stable red phosphor is the key to solving this problem. In this work, a series of pure CaYBO:Eu (0 < ≤ 2) samples, including the new and fully transitional borate phosphor CaEuBO (CEBO), have been successfully prepared by solid-state reaction synthesis.

Large optical polarizability causing positive effects on the birefringence of planar-triangular BO groups in ternary borates.

The structure-property relationship of photoelectric functional materials has been recognized as a hot topic. The study of the inner link between the band gaps and birefringence of optical materials is extremely crucial for the design and creation of novel optical devices, but still remains rather unexplored. In this work, taking a series of borates with only planar-triangular BO groups, α-/β-TM(BO) (TM = Zn, Cd), CdBO, and M(BO) (M = Hg, Mg, Ca, Sr) as the research subject, the comprehensive relationship between their electronic structures and linear optical properties has been systematically investigated.

Efficient and stable SrEuBO red phosphor benefiting from low symmetry and distorted local environment.

The development of suitable red phosphors to obtain improved white color stands a good chance to serve in the new generation of white light-emitting diodes. Owing to multi-elements via doping and oxidation of reduced valence state of lanthanide or transition metal ions, most of the reported phosphors usually suffer from complex synthetic processes and unstable color of the lighting industry cycle. In this work, we present a new red emitting and stable SrEuBO phosphor with regard to its special structure.

Tuning of Emission by Eu Concentration in a Pyrophosphate: the Effect of Local Symmetry.

The local symmetry of a Eu ion has a crucial effect on its luminescence properties. In this work, we show that the red/orange ratio in the emission of Eu-doped MgInPO phosphors is tunable by adjusting the Eu concentrations, due to the change in the local symmetry of metal ions. The substitution of Eu for In lowers the distortion in the lattice of monoclinic MgInPO, and an increase in Eu doping concentration causes the metal ion sites to shift closer to an inverse center, leading to a reversal of the relative emission intensity of a magnetic dipole transition to an electric dipole transition.

Enhanced thermoelectric properties in N-type MgSi SnSb synthesized by alkaline earth metal reduction.

MgSi Sn -based compounds have been recognized as promising thermoelectric materials owing to their high figure-of-merit s, abundance of raw constituent elements and nontoxicity. However, further improvement in the thermoelectric performance in this type of material is still constrained by the high thermal conductivity. In this work, we prepared a series of representative MgSi SnSb ( = 0, 0.

Structure, tunable luminescence and energy transfer in Tb and Eu codoped BaInBO phosphors.

The borate BaInBO (BIBO) is a promising host material for phosphors. A series of Tb and Eu codoped BaInBO phosphors were synthesized. Based on the Rietveld method, structure refinement of the codoped BIBO phosphor was carried out.

Improvement of thermoelectric performance of copper-deficient compounds Cu InTe ( = 0-0.15) due to a degenerate impurity band and ultralow lattice thermal conductivity.

Cu-In-Te ternary chalcogenides have unique crystal and band structures; hence they have received much attention in thermoelectrics. In this work we have observed an enhancement in Hall carrier concentration ( ) and ultralow lattice thermal conductivity ( ) when Cu was added to ternary Cu InTe ( = 0-0.15) compounds.

Increased effective mass and carrier concentration responsible for the improved thermoelectric performance of the nominal compound CuGaTe with Sb substitution for Cu.

Although the ternary chalcopyrite compound CuGaTe has relatively high thermal conductivity and electrical resistivity, it has a high carrier concentration, thus making it a good thermoelectric candidate. In this work we substitute Sb for Cu in this compound, aiming at engineering both the electrical and thermal properties. Rietveld refinement revealed that the nominal compounds Cu Sb GaTe ( = 0-0.

Layered Crystal Structure, Color-Tunable Photoluminescence, and Excellent Thermal Stability of MgInPO Phosphate-Based Phosphors.

Single-component white phosphors stand a good chance to serve in the next-generation high-power white light-emitting diodes. Because of low thermal stability and containing lanthanide ions with reduced valence state, most of reported phosphors usually suffer unstable color of lighting for practical packaging and comparably complex synthetic processes. In this work, we present a type of novel color-tunable blue-white-yellow-emitting MgInPO:Tm/Dy phosphor with high thermal stability, which can be easily fabricated in air.