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Colloidal all‐inorganic lead halide perovskite nanocrystals (LHP NCs) feature with tunable high‐efficiency photoluminescence from blue to red for optoelectronic applications but suffer from instability under water moisture, UV light illumination, high‐temperature shock, as well as oxygen erosion. Previous work to improve LHP NCs stability was mainly focused on either glass bulk sealed LHP quantum dots (QDs) with low quantum efficiency, or mesoporous silica matrixes confined LHP QDs with organic ligands still existing. Here, a facile, noncolloidal, ligand‐free LHP QDs growth with physical confinement is proposed by integrating the growth of perovskite QDs with the fabrication process of hydrophobic silica‐aerogel powders (SAPs). As a result, the as‐synthesized mono‐ and mixed‐cesium‐lead‐halide QDs @ SAPs composites show tunable photoluminescence from purple to deep red. Besides, the Pr3+ ions doped CsPbBr3 QDs @ SAPs composites exhibit moderate quantum efficiency, excellent stability under UV illumination, water moisture as well as temperature variation. Furthermore, performances of white LED device encapsulated Pr3+ doped composite with blue GaN chip and commercial red (Sr, Ca)AlSiN3:Eu2+ phosphor are evaluated. This work demonstrates a facile and general strategy for synthesizing high‐stable all‐inorganic cesium‐lead‐halide QDs for applications in white LED and display devices. [ABSTRACT FROM AUTHOR]

Disk transparent ceramics with multilayer composite structure serves well as laser gain medium because of its excellent thermal and optical properties. For such a type of material, the preparation of corresponding outstanding slurry is the first yet most essential step, and it may determine the quality of both subsequent green tape and the sintered ceramics. In this work, the tape‐casting slurry with typically pseudoplastic behavior was carefully modulated in the mixture solvent of anhydrous ethanol and ethyl acetate, and its rheological property was systematically investigated using fine‐controlled rotary rheometer. The obtained result reveals 4wt.% fish oil to be the best dispersed agent. With the obtained slurry for tape‐casting followed by lamination and warm isostatic‐pressing, the multilayer ultrathin TCs was successfully fabricated via high‐temperature vacuum sintering technology. The obtained full‐dense microstructure with high optical quality may endow the studied ceramic with great potential for highly efficient solid‐state laser gain medium. [ABSTRACT FROM AUTHOR]

Yb3+-doped LuAG laser ceramics with different Yb3+-doping concentrations were successfully fabricated by nonaqueous tape casting method and vacuum sintering technology. XRD patterns and SEM morphologies of the ceramics were presented. The optical in-line transmittance of the Yb-doped LuAG ceramics was about 83% at 1030 nm. The fluorescence lifetime of annealed and unannealed ceramic samples was compared. From the spectroscopic properties, it can be seen that the ceramics had a large emission cross section of 2.9 3 10-20 cm² with a FWHM of about 7.2 nm at 1030 nm. Under 100% population inversion, the maximum gain coefficient was estimated to be 12.4 cm-1 at 1030 nm. With a fiber-coupled diode laser as pump source, CW laser at 1030 nm was demonstrated and the maximum output power of 338.9 mW was achieved with a slop efficiency of 19%. A tuning range from 1028 to 1036 nm was obtained. [ABSTRACT FROM AUTHOR]

YAG:Ce phosphors are synthesized by the vacuum sintering method, and their crystal structure, luminescence properties, and X-ray photoelectron spectroscopy are discussed. The synthesized temperature of pure YAG phase is reduced by vacuum sintering. As-synthesized YAG:Ce phosphors show a smaller average size of about 1mm due to the fine starting materials, low sintering temperature, and the absence of flux. It is found that samples synthesized by the vacuum sintering method show stronger emission intensity and higher optimized Ce3+-doping concentration. In addition, white light-emitting diodes (LEDs) with improved color-rendering properties are obtained by using modified Pr3+-doped YAG:Ce phosphors. [ABSTRACT FROM AUTHOR]

Fifteen layers' composite YAG/Yb:YAG/YAG laser ceramic with grain size of about 5 μm was fabricated through tape casting process together with vacuum sintering technology, and its microstructure, optical properties, and laser performance were investigated. The experimental results showed that annealing in oxygen atmosphere could remove the lattice distortion and improve the optical transmittance. The in-line transmittance was 83% at 800 nm. The laser study indicated that the threshold pump power was 5.5 W with output coupler transmission of 6% and slope efficiency achieved 12%. The maximum output power of 0.53 W was achieved at the absorbed pump power of 10 W. [ABSTRACT FROM AUTHOR]