4 research outputs found
Highly Stable K<sub>2</sub>SiF<sub>6</sub>:Mn<sup>4+</sup>@K<sub>2</sub>SiF<sub>6</sub> Composite Phosphor with Narrow Red Emission for White LEDs
Poor
water resistance and nongreen synthesis remain great challenges for
commercial narrow red-emitting phosphor A<sub>2</sub>MF<sub>6</sub>:Mn<sup>4+</sup> (A = alkali metal ion; M = Si, Ge, Ti) for solid-state
lighting and display. We develop here a simple and green growth route
to synthesize homogeneous red-emitting composite phosphor K<sub>2</sub>SiF<sub>6</sub>:Mn<sup>4+</sup>@K<sub>2</sub>SiF<sub>6</sub> (KSFM@KSF)
with excellent water resistance and high efficiency without the usage
of toxic and volatile hydrogen fluoride solution. After immersing
into water for 6 h, the as-obtained water-resistant products maintain
76% of the original emission intensity, whereas the emission intensity
of non-water-resistant ones steeply drops down to 11%. A remarkable
result is that after having kept at 85% humidity and at 85 °C
for 504 h (21 days), the emission intensity of the as-obtained water-resistant
products is at 80–90%, from its initial value, which is 2–3
times higher than 30–40% for the non-water-resistant products.
The surface deactivation-enabled growth mechanism for these phosphors
was proposed and investigated in detail. We found that nontoxic H<sub>3</sub>PO<sub>4</sub>/H<sub>2</sub>O<sub>2</sub> aqueous solution
promotes the releasing and decomposition of the surface [MnF<sub>6</sub>]<sup>2–</sup> ions and the transformation of the KSFM surface
to KSF, which finally contributes to the homogeneous KSFM@KSF composite
structure. This composite structure strategy was also successfully
used to treat KSFM phosphor prepared by other methods. We believe
that the results obtained in the present paper will open the pathway
for the large-scale environmentally friendly synthesis of the excellent
antimoisture narrow red-emitting A<sub>2</sub>MF<sub>6</sub>:Mn<sup>4+</sup> phosphor to be used for white light-emitting diode applications
Thermally Stable White Emitting Eu<sup>3+</sup> Complex@Nanozeolite@Luminescent Glass Composite with High CRI for Organic-Resin-Free Warm White LEDs
Nowadays,
it is still a great challenge for lanthanide complexes to be applied
in solid state lighting, especially for high-power LEDs because they
will suffer severe thermal-induced luminescence quenching and transmittance
loss when LEDs are operated at high current. In this paper, we have
not only obtained high efficient and thermally chemical stable red
emitting hybrid material by introducing europium complex into nanozeolite
(NZ) functionalized with the imidazolium-based stopper but also abated
its thermal-induced transmittance loss and luminescence quenching
behavior via coating it onto a heat-resistant luminescent glass (LG)
with high thermal conductivity (1.07 W/mK). The results show that
the intensity at 400 K for EuÂ(PPO)<sub><i>n</i></sub>-C<sub>4</sub>Si@NZ@LG remains 21.48% of the initial intensity at 300 K,
which is virtually 153 and 13 times the intensity of EuÂ(PPO)<sub>3</sub>·2H<sub>2</sub>O and EuÂ(PPO)<sub><i>n</i></sub>-C<sub>4</sub>Si@NZ, respectively. Moreover, an organic-resin-free warm
white LEDs device with a low CCT of 3994K, a high Ra of 90.2 and R9
of 57.9 was successfully fabricated simply by combining NUV-Chip-On-Board
with a warm white emitting glass-film composite (i.e., yellowish-green
emitting luminescent glass coated with red emitting hybrid film).
Our method and results provide a feasible and promising way for lanthanide
complexes to be used for general illumination in the future
All-Inorganic Light Convertor Based on Phosphor-in-Glass Engineering for Next-Generation Modular High-Brightness White LEDs/LDs
Superhigh
brightness, reliability, and modularization are three key features
of state-of-the-art high-brightness solid state lighting, such as
high-power white light-emitting diodes (white LEDs) and white laser
diodes (white LDs). However, these features are inevitably limited
by the organic resin packing material, as a crucial component of the
white lighting device, because of its unstable property at high temperature
and low thermal conductivity. Here, we report a robust light convertor
that can simultaneously play key roles as a phosphor and an alternative
encapsulating material via phosphor-in-glass (PiG) engineering. We
employed a combination of powder X-ray diffraction, scanning electron
microscope, energy dispersive spectrometer (EDS), EDS mapping, confocal
laser scanning microscope, cathodoluminescence mapping, in conjunction
with micro-PL system with a point-by-point scanning mode to study
the detailed structure of PiG samples. This Y<sub>3</sub>Al<sub>5</sub>O<sub>12</sub>:Ce<sup>3+</sup>-based PiG exhibits a high external
quantum efficiency of ∼60%, a high thermal conductivity of
∼0.59 W/mK, exceptional thermal stability, and excellent moisture
resistance. By combining the as-synthesized PiG with high-power blue
chip-on-board, a high luminous efficacy (92 lm/W) modular white LEDs
with a luminous flux up to 1076 lm and a high color rendering modular
warm white LEDs (Ra = 90.3 and CCT = 3585 K) are achieved. Moreover,
a modular white LDs with a higher luminous efficacy (110 lm/W) is
also achieved through blue LDs pumping. The results demonstrate that
this easy-fabrication, low-cost, and long-term reliable high-brightness
modular white LEDs or white LDs is expected to be a promising candidate
for next-generation illumination
Additional file 1 of Metagenome-wide analysis uncovers gut microbial signatures and implicates taxon-specific functions in end-stage renal disease
Additional file 1: Table S1. Summary on statistics of the host properties and clinical parameters from the Shanghai and Beijing cohorts. Table S2. Summary of deep whole-metagenomic shotgun sequencing data production of this study. Table S3. Detailed information of data production, assembly, and MAG reconstruction of 715 samples. Table S4. Detailed information of 1303 non-redundant microbial species reconstructed from the fecal metagenomes of this study. Table S5. Detailed information of the 100 most discriminant species in the random forest regression models of the Shanghai and Beijing cohorts. Table S6. Detailed information of 353 ESRD-associated species. Table S7. Detailed information of 1279 ESRD-associated KOs. Table S8. Detailed information of 103 ESRD-associated KEGG functional modules. Table S9. Detailed information of 3,009 ARGs identified in this study. Table S10. Detailed information of 730 KOs that significantly differed in occurrence frequency between ESRD-enriched and HC-enriched Firmicutes species. Table S11. Detailed information of 40 modules that significantly differed in integrity between ESRD-enriched and HC-enriched Firmicutes species. Table S12. Detailed information of 67 gut species with the highest contribution of uremic toxin levels in serum. Table S13. Abundances and statistical test of 353 ESRD-associated species among the CKD patients vs. healthy controls