White Light Emission from Pr, Dy Doped ZnSiCa Glass

2020 ◽  
Vol 12 (2) ◽  
pp. 154-160
Author(s):  
Pingsheng Yu ◽  
Wei Guo ◽  
Yilu Cheng ◽  
Liangbi Su ◽  
Jun Xu
Keyword(s):  
White Light ◽  
Light Emission ◽  
Light Emitting Diode ◽  
Visible Region ◽  
Color Temperature ◽  
Potential Candidate ◽  
Rare Earth Ion ◽  
Light Emitting ◽  
Light Region ◽  
Chromaticity Coordinates

Background:: Luminescence glass is a potential candidate for developing white light emitting diode (W-LED) due to its good rare earth ion solubility, efficient luminescence, easy fabrication and good mold ability. Pr3+ ion has various visible emission bands from blue to red spectral region, and has attracted considerable attention for potential application to LEDs, ultraviolet laser, and scintillator. The Dy3+ ions can exhibit emission in blue and greenish-yellow (4F9/2→6H15/2, 13/2 transitions of Dy3+) spectral regions under excitation at near UV (ultraviolet). It is possible to obtain white luminescence if Pr3+ ions and Dy3+ ions can be excited simultaneous, due to their multiple luminescence in the visible region. Methods: The Pr, Dy doped ZnSiCa glass samples were prepared by the conventional melting quenching procedure. The XRD, absorption spectra, emission spectra, and ICP-OES measurements were performed to investigate the properties of the materials. Results: The Pr and Dy co-doped ZnSiCa glasses under 443 nm excitation show emission band peaking at about 483 nm, 575 nm and 670 nm / 676 nm. The glass samples exhibit chromaticity coordinates in the white light region in the CIE 1931 diagram, with a Correlated Color Temperature (CCT) at about 7000 K. Conclusion: Pr, Dy codoped ZnSiCa glass samples show chromaticity coordinates in the white light region in the CIE 1931 diagram, with a CCT at about 7000 K. It is suggested that the Pr, Dy codoped ZnSiCa glasses might be considered as promising candidates for white light emitting sources.

scholarly journals Chromaticity Study of Curcumin Dye Extracted from Curcuma longa L. Using for UV Light down Conversion for White Light Emitting Diode

2019 ◽  
Vol 290 ◽  
pp. 183-189
Author(s):  
Mahmood Al Shafouri ◽  
Naser Mahmoud Ahmed ◽  
Zainuriah Hassan ◽  
Munirah Abdullah Almessiere
Keyword(s):  
White Light ◽  
Uv Light ◽  
Light Emitting Diode ◽  
Curcuma Longa ◽  
Color Temperature ◽  
Light Emitting ◽  
Chromaticity Coordinates ◽  
Major Factors ◽  
Color Rendering ◽  
Down Conversion

In thus study, Turmeric phosphor dye was extracted from Curcuma Longa L. via a simple technique using silica gel. The phosphor was used for light down-conversion of UV light for the manufacture white light emitting diode (WLED). The UV-LED was analyzed over 395nm wavelengths. The characteristics of the white light chromaticity were controlled by tuning the current and phosphor concentration. An optimum color rendering index (CRI) value of 63.4 was obtained. The chromaticity coordinates (CIE) and correlated color temperature (CCT) were measured for various currents and phosphor concentrations. The white phosphor exhibited CIE value of 0.355,0.338 and CCT of 4567 K. The concentration of phosphor and amount of applied current were confirmed to be major factors that control the intensity of white light emitted from the sample, where CIE and CRI of the emitted light steadily increased with the concentration of phosphor and current. Thus, phosphor concentration has a critical effect on conversion efficiency. Key words: Turmeric, phosphor, WLED, curcumin

scholarly journals Study of the Effect of Injection Currents on White Light Emission of Ce-Doped YAG Phosphor Powder Prepared by Microwave Combustion

2020 ◽  
Vol 301 ◽  
pp. 60-68 ◽  
Author(s):  
Husnen R. Abd ◽  
Zainuriah Hassan ◽  
Naser Mahmoud Ahmed ◽  
A.F. Omar ◽  
Khai Shenn Lau ◽  
...  
Keyword(s):  
White Light ◽  
Yttrium Aluminum Garnet ◽  
Light Emission ◽  
Light Emitting Diode ◽  
Spherical Particles ◽  
Color Temperature ◽  
Phosphor Powder ◽  
Light Emitting ◽  
Microwave Combustion ◽  
Whole Process

The behaviors of yttrium aluminum garnet (YAG) phosphor powder doped by cerium (YAG:Ce3+) was studied. Here, the YAG:Ce3+ nanopowders have been synthesized using microwave combustion (MW) according to the formula, Y(3-0.04) Al5O12: 0.04Ce3+ to produce white light emitting diode (WLEDs) by conversion from blue indium gallium nitride light emitting diode (InGaN LED, 445 nm) chips; the whole process took only 20 min. Pure YAG phase was obtained after annealing at 1050 °C for 5 h with nonaggregated and spherical particles. Thermogravimetry and derivative thermogravimetry (TG/DTG), X-ray powder diffraction (XRPD), transmission electron microscope (TEM), photoluminescence (PL), electroluminescence (EL) emissions and standard CIE 1931 chromaticity diagrams have been used to characterize the samples. The highest WLEDs emission was achieved for the annealed YAG:Ce3+, together with proper color rendering index (CRI), and tunable correlated color temperature (CCT). Finally, we conclude that the decreasing EL intensity at increased injection current is caused by the thermal ionization from the 5d1 level to the conduction band.

White light emission from a blue polymer light emitting diode combined with YAG:Ce3+ nanoparticles

2013 ◽  
Vol 211 (3) ◽  
pp. 651-655 ◽  
Author(s):  
Jorge Oliva ◽  
Elder De la Rosa ◽  
Luis Diaz-Torres ◽  
Anvar Zakhidov
Keyword(s):  
White Light ◽  
Light Emission ◽  
Light Emitting Diode ◽  
White Light Emission ◽  
Light Emitting ◽  
Polymer Light Emitting Diode

scholarly journals Near Unity PLQY and High Stability of Barium Thiocyanate Based All-Inorganic Perovskites and Their Applications in White Light-Emitting Diodes

Photonics ◽  
2021 ◽  
Vol 8 (6) ◽  
pp. 209
Author(s):  
Gopi Chandra Adhikari ◽  
Saroj Thapa ◽  
Yang Yue ◽  
Hongyang Zhu ◽  
Peifen Zhu
Keyword(s):  
White Light ◽  
Large Scale ◽  
Light Emitting Diode ◽  
Photophysical Properties ◽  
Environmental Stability ◽  
Color Temperature ◽  
Ambient Atmosphere ◽  
Light Emitting ◽  
Halide Perovskite ◽  
Lead Halide

All-inorganic lead halide perovskite (CsPbX3) nanocrystals (NCs) have emerged as a highly promising new generation of light emitters due to their extraordinary photophysical properties. However, the performance of these semiconducting NCs is undermined due to the inherent toxicity of lead and long-term environmental stability. Here, we report the addition of B-site cation and X-site anion (pseudo-halide) concurrently using Ba(SCN)2 (≤50%) in CsPbX3 NCs to reduce the lead and improve the photophysical properties and stability. The as-grown particles demonstrated an analogous structure with an almost identical lattice constant and a fluctuation of particle size without altering the morphology of particles. Photoluminescence quantum yield is enhanced up to near unity (~98%) by taking advantage of concomitant doping at the B- and X-site of the structure. Benefitted from the defect reductions and stronger bonding interaction between Pb2+ and SCN− ions, Ba(SCN)2-based NCs exhibit improved stability towards air and moisture compared to the host NCs. The doped NCs retain higher PLQY (as high as seven times) compared to the host NCs) when stored in an ambient atmosphere for more than 176 days. A novel 3D-printed multiplex color conversion layer was used to fabricate a white light-emitting diode (LED). The obtained white light shows a correlated color temperature of 6764 K, a color rendering index of 87, and luminous efficacy of radiation of 333 lm/W. In summary, this work proposes a facile route to treat sensitive lead halide perovskite NCs and to fabricate LEDs by using a low-cost large-scale 3-D printing method, which would serve as a foundation for fabricating high-quality optoelectronic devices for near future lighting technologies.

scholarly journals Effects of Bi3+ Ion-Doped on the Microstructure and Photoluminescence of La0.97Pr0.03VO4 Phosphor

2021 ◽  
Vol 6 (3) ◽  
pp. 191-198
Author(s):  
Hao-Long Chen ◽  
Hung-Rung Shih ◽  
Sean Wu ◽  
Yee-Shin Chang
Keyword(s):  
White Light ◽  
Emission Intensity ◽  
Sol Gel ◽  
Blue Shift ◽  
Light Emitting ◽  
Light Region ◽  
Chromaticity Coordinates ◽  
Ion Doping ◽  
Ion Contents ◽  
Cie Chromaticity

The objective of this paper is to enhance the emission intensity of La0.97Pr0.03VO4 single-phased white light emitting phosphor. The Bi3+ ion-doped La0.97Pr0.03VO4 single-phased white light emitting phosphors are synthesized using a sol-gel method. The structure and photoluminescence properties of (La0.97-yBiy)Pr0.03VO4 (y = 0-0.05) phosphor are also examined. The XRD results show that the structure of La0.97Pr0.03VO4 phosphors with different concentrations of Bi3+ ion doping keeps the monoclinic structure. The SEM results show that the phosphor particles become smoother when the Bi3+ ion is doped. The excitation band for La0.97Pr0.03VO4 phosphor exhibits a blue shift from 320 nm to 308 nm as the Bi3+ ion contents are increased. The maximum emission intensity is achieved for a Bi3+ ion content of 0.5 mol%, which is about 30% greater than that with no Bi3+ ion doped. The CIE chromaticity coordinates are all located in the near white light region for different Bi3+ ion-doped La0.97Pr0.03VO4 phosphors.

A Monolithic White-Light LED Based on GaN Doped with Be

2014 ◽  
Vol 93 ◽  
pp. 264-269 ◽  
Author(s):  
Henryk Teisseyre ◽  
Michal Bockowski ◽  
Toby David Young ◽  
Szymon Grzanka ◽  
Yaroslav Zhydachevskii ◽  
...  
Keyword(s):  
Gallium Nitride ◽  
White Light ◽  
Light Emission ◽  
Light Emitting Diode ◽  
Yellow Emission ◽  
Bulk Crystals ◽  
Light Emitting ◽  
Type Conductivity ◽  
P Type ◽  
Colour Rendering

In this communication, the use of gallium nitride doped with beryllium as an efficient converter for white light emitting diode is proposed. Until now beryllium in this material was mostly studied as a potential p-type dopant. Unfortunately, the realization of p-type conductivity in such a way seems impossible. However, due to a very intensive yellow emission, bulk crystals doped with beryllium can be used as light converters. In this communication, it is demonstrated that realisation of such diode is possible and realisation of a colour rendering index is close to that necessary for white light emission.

Synthesis and luminescence properties of the red phosphor CaZrO3:Eu3+ for white light-emitting diode application

Open Physics ◽  
2011 ◽  
Vol 9 (4) ◽  
Author(s):  
Junli Huang ◽  
Liya Zhou ◽  
Yuwei Lan ◽  
Fuzhong Gong ◽  
Qunliang Li ◽  
...  
Keyword(s):  
White Light ◽  
Light Emitting Diode ◽  
Red Light ◽  
Average Diameter ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Solid State Method ◽  
Light Emitting ◽  
Near Ultraviolet ◽  
Light Region

AbstractEu3+-doped CaZrO3 phosphor with perovskite-type structure was synthesized by the high temperature solid-state method. The samples were characterized by X-ray diffraction, scanning electron microscopy, fluorescence spectrophotometer and UV-vis spectrophotometer, respectively. XRD analysis showed that the formation of CaZrO3 was at the calcinations temperature of 1400°C. The average diameter of CaZrO3 with 4 mol% doped-Eu3+ was 2µm. The PL spectra demonstrated that CaZrO3:Eu3+ phosphor could be excited effectively in the near ultraviolet light region (397 nm) and emitted strong red-emission lines at 616 nm corresponding to the forced electric dipole 5 D 0 → 7 F 2 transitions of Eu3+. Meanwhile, the light-emitting diode was fabricated with the Ca0.96ZrO3:Eu0.043+ phosphor, which can efficiently absorb ∼ 400 nm irradiation and emit red light. Therefore Ca0.96ZrO3:Eu0.043+ may have applications for a near ultraviolet InGaN chip-based white light-emitting diode.

Tunable luminescence from Sm3+, Ce3+ codoped Al2O3–La2O3–SiO2 glasses for white light emission

2009 ◽  
Vol 24 (5) ◽  
pp. 1730-1734 ◽  
Author(s):  
Hucheng Yang ◽  
G. Lakshminarayana ◽  
Yu Teng ◽  
Shifeng Zhou ◽  
Jianrong Qiu
Keyword(s):  
Energy Transfer ◽  
White Light ◽  
Spectral Properties ◽  
Light Emission ◽  
Light Emitting Diode ◽  
Fluorescence Decay ◽  
White Light Emission ◽  
Luminescence Properties ◽  
Light Emitting ◽  
Luminescence Efficiency

Sm3+, Ce3+ codoped Al2O3–La2O3–SiO2 glasses were prepared and their luminescence properties were characterized. Blue-cyan to orange-red tunable luminescence was observed from these glasses with different excitation wavelengths ranging from 385 to 410 nm. White light emission with internal luminescence efficiency 42% has been observed using commercially available purple light-emitting-diode excitation. The energy transfer between Ce3+ and Sm3+ has also been investigated from fluorescence decay curves and spectral properties.

Photo-facilitated aggregation and correlated color temperature adjustment of single component organic solid state white-light emitting materials

2015 ◽  
Vol 3 (17) ◽  
pp. 4563-4569 ◽  
Author(s):  
Cheng Chen ◽  
Xu-Hui Jin ◽  
Xue-Jun Zhou ◽  
Li-Xuan Cai ◽  
Ya-Jun Zhang ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Solid State ◽  
White Light ◽  
Light Emission ◽  
White Light Emission ◽  
Single Component ◽  
Color Temperature ◽  
Dual Emission ◽  
Light Emitting ◽  
Organic Solid

A pyridinium derivative with photo-facilitated aggregation and intra-/intermolecular charge transfer synergy-induced dual emission has been presented. The correlated color temperature tunable white-light emission can be realized in different states.

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