scholarly journals Chromaticity-Tunable and Thermal Stable Phosphor-in-Glass Inorganic Color Converter for High Power Warm w-LEDs

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1792 ◽  
Author(s):  
Zikun Chen ◽  
Bo Wang ◽  
Xiaoshuang Li ◽  
Dayu Huang ◽  
Hongyang Sun ◽  
...  
Keyword(s):  
High Power ◽  
Energy Dispersive Spectrometer ◽  
Color Temperature ◽  
Photoluminescence Intensity ◽  
White Led ◽  
Mapping Analysis ◽  
Yellow Orange ◽  
Color Rendering ◽  
Silicate Garnet ◽  
Thermal Stable

In this work, an aluminate silicate garnet phosphor, Y2Mg2Al2Si2O12:Ce3+ (YMASG:Ce3+), exhibiting strong and broad yellow-orange emission, was successfully synthesized. Attributed to the double cation substitution of YAG:Ce3+, which led to a compression effect, a redshift was observed with respect to YAG:Ce3+. More importantly, a transparent phosphor-in-glass (PiG) sample was obtained by incorporating the phosphor YMASG:Ce3+ into a special low-melting precursor glass. The energy dispersive spectrometer (EDS) mapping analysis of the as-prepared PiG sample indicates that YMASG:Ce3+ was successfully incorporated into the glass host, and its powders were uniformly distributed in glass. The photoluminescence intensity of the PiG sample was higher than that of the powder due to its relatively high thermal conductivity. Additionally, the combination of the PiG sample and a blue high-power chip generated a modular white LED with a luminous efficacy of 54.5 lm/W, a correlated color temperature (CCT) of 5274 K, and a color rendering index (CRI) of 79.5 at 350 mA.

scholarly journals Efficient spectral regulation in Ce:Lu3(Al,Cr)5O12 and Ce:Lu3(Al,Cr)5O12/Ce:Y3Al5O12 transparent ceramics with high color rendering index for high-power white LEDs/LDs

2021 ◽  
Author(s):  
Tianyuan Zhou ◽  
Chen Hou ◽  
Le Zhang ◽  
Yuelong Ma ◽  
Jian Kang ◽  
...  
Keyword(s):  
Thermal Stability ◽  
High Power ◽  
White Led ◽  
Transparent Ceramics ◽  
Photoluminescence Excitation ◽  
Unilateral Shift ◽  
Excitation Mode ◽  
White Leds ◽  
Color Rendering Index ◽  
Color Rendering

AbstractRealizing a high color rendering index (CRI) in Ce:LuAG transparent ceramics (TCs) with desired thermal stability is essential to their applications in white LEDs/LDs as color converters. In this study, based on the scheme of configuring the red component by Cr3+ doping, an efficient spectral regulation was realized in Ce,Cr:LuAG TCs. A unilateral shift phenomenon could be observed in both photoluminescence (PL) and photoluminescence excitation (PLE) spectra of TCs. By constructing TC-based white LED/LD devices in a remote excitation mode, luminescence properties of Ce,Cr:LuAG TCs were systematically investigated. The CRI values of Ce:LuAG TC based white LEDs could be increased by a magnitude of 46.2%. Particularly, by combining the as fabricated Ce,Cr:LuAG TCs with a 0.5 at% Ce:YAG TC, surprising CRI values of 88 and 85.5 were obtained in TC based white LEDs and LDs, respectively. Therefore, Ce,Cr:LuAG TC is a highly promising color convertor for high-power white LEDs/LDs applied in general lighting and displaying.

Compatibility of Photoluminescence Properties in ScPO4:Eu3+, Tb3+ Phosphor for White Light Emitting Diodes

2021 ◽  
Vol 21 (12) ◽  
pp. 5890-5895
Author(s):  
Jian Zhou ◽  
Jian-Wen Zhao ◽  
Si-Li Ren ◽  
Jun Dong
Keyword(s):  
The Body ◽  
Color Temperature ◽  
White Led ◽  
Photoluminescence Properties ◽  
Light Emitting ◽  
Co Doping ◽  
Emission Color ◽  
Single Matrix ◽  
White Light Emitting Diodes ◽  
Color Rendering

ScPO4:Eu3+, Tb3+ phosphors with tuned emission color were prepared through high temperature solid-state reaction. The structure, morphology and photoluminescence properties of the title samples were collected by XRD, SEM and fluorescence spectrophotometer, respectively. Co-doping Eu3+ and Tb3+ in ScPO4 does not change the body-centered tetragonal structure of the host. And the morphology remains essentially unchanged except for slight agglomeration. Changing the ratio of Tb3+/Eu3+, the tuned emission can be achieved, the color could be adjusted from green through yellow to orange-red. The ScPO4:0.03Tb3+, 0.03Eu3+ phosphor with high thermal stability as the single matrix phosphor can be suitable for the NUV-pumped white LED. The white LED with a color rendering index of 86.5 and a correlated color temperature of 3470 K has been generated by packaging BAM:Eu2+ with ScPO4:0.03Tb3+, 0.03Eu3+ on an NUV-InGaN chip.

Study on Tunable Color Temperature White LED Light Source with Ultra-High Color Rendering Index

2015 ◽  
Vol 35 (10) ◽  
pp. 1023002
Author(s):  
谌江波 Chen Jiangbo ◽  
余建华 Yu Jianhua ◽  
高亚飞 Gao Yafei ◽  
张翼扬 Zhang Yiyang ◽  
陆秀炎 Lu Xiuyan
Keyword(s):  
Light Source ◽  
Color Temperature ◽  
White Led ◽  
Led Light ◽  
Color Rendering Index ◽  
Color Rendering

Effects of Sintering Route and Flux on the Luminescence and Morphology of YAG: Ce Phosphors for White Emitting-Light Diodes (LEDs)

2012 ◽  
Vol 236-237 ◽  
pp. 9-15
Author(s):  
Tao Han ◽  
Shi Xiu Cao ◽  
Ming Xing Ma ◽  
Da Chuan Zhu ◽  
Cong Zhao ◽  
...  
Keyword(s):  
White Light ◽  
Potential Application ◽  
Color Temperature ◽  
Precipitation Method ◽  
Photoluminescence Intensity ◽  
White Led ◽  
White Leds ◽  
Chromaticity Coordinates ◽  
Co Precipitation ◽  
Surface Morphologies

YAG:Ce phosphors were synthesized by co-precipitation method. The photoluminescence intensity of samples sintered by the two-step route increases by about 10%, and with 0.5 wt.% NH4Cl added as flux, surface morphologies and size distribution are improved. The white LEDs were fabricated using as-obtained phosphors. It shows natural white light with chromaticity coordinates of (0.3083, 0.3163), color temperature (Tc) of 6886 K, the average CRI of 75, and the luminous efficacy of 85 ml/W. Therefore, The as-obtained YAG:Ce phosphors could be regard to have potential application in white LED devices.

scholarly journals Multi-functional semiconductor lighting

2020 ◽  
pp. 62-74
Author(s):  
Irina Palchikova ◽  
◽  
Elena Karamchuk ◽  
Evgenii Smirnov ◽  
Eugeny Palchikov ◽  
...  
Keyword(s):  
Experimental Model ◽  
Spectral Range ◽  
Digital Images ◽  
Color Temperature ◽  
White Led ◽  
Color Rendering Index ◽  
Multispectral Analysis ◽  
Color Rendering ◽  
Lighting Variation

Features of the development of the multifunctional semiconductor illuminators are discussed. The design and characteristics of the experimental model of the “Photobox 3138” illuminator are described. The lighting variation does not exceed 2 % at the edges of the working field of 300*300 mm. The design includes a white LED illuminator with a color temperature of 5000 K (CIE D50) and a high color rendering index (CRI 97+) and a set of six independently switched monochrome led illuminators in the spectral range from 365 to 880 nm. Digital images of objects obtained in “Photobox 3138” are of use to colorimetric, spectrozonal, and multispectral analysis.

scholarly journals Improving Lighting Performance of High Color Temperature White LED Packages Using (La,Ce,Tb) PO4:Ce:Tb Phosphor

2017 ◽  
Vol 1 (2) ◽  
pp. 87
Author(s):  
Thi Phuong Thao Nguyen ◽  
Doan Quoc Anh Nguyen ◽  
Miroslav Voznak ◽  
Van Tho Le
Keyword(s):  
Optimal Solution ◽  
Color Temperature ◽  
White Led ◽  
Particle Size Range ◽  
Green Phosphor ◽  
Creative Commons ◽  
Quality Scale ◽  
Color Uniformity ◽  
Color Rendering ◽  
Open Access Article

Enhancement of the color uniformity, the lumen output of the multi-chip white LED lamps (MCW-LEDs) at high color correlated temperature is a big challenge for researchers. However, an innovative LED lamp designed with a phosphor compounding, which combines (La,Ce,Tb) PO4:Ce:Tb (LaTb) green phosphor with YAG: CE yellow phosphor, is proposed as an optimal solution to this requirement. Index, using LaTb green phosphor into MCWLEDs could bring a superior optical performance for MCW-LEDs. It is found that the lumen output of this new MCW-LED at a high color temperature of 8500 K significantly improves up to 1600 lm compared to MCW-LEDs without LaTb phosphor. The simulation results demonstrated that the CCT deviation sharply decreases from 9000 to 1000 at the LaTb concentration range from 0 to 1.8 %, while the Color Rendering Index ability (CRI) and the Color Quality Scale (CQS) slightly decrease. To obtain the highest lumen output and the best color uniformity, the particle size range within 6 - 8 µm should be suggested.  This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Analysis and Research of the High Power LED Temperature Characteristics

2013 ◽  
Vol 710 ◽  
pp. 460-463
Author(s):  
Qi Li Liao ◽  
Ting Ting Lang ◽  
Fei Lv
Keyword(s):  
High Power ◽  
Apparent Temperature ◽  
Color Temperature ◽  
Integrating Sphere ◽  
White Led ◽  
Color Purity ◽  
Forward Voltage ◽  
Temperature Characteristics ◽  
Color Coordinates ◽  
High Power Led

This paper is mainly about the high power LED temperature characteristics. With the integrating sphere, we conduct an experiment to observe and analysis the relationships of temperature and color coordinates, peak wavelength, color temperature, forward voltage, peak bandwidth, color purity, electric power. Finally we get that the temperature is the main factor to affect the color performance of white LED photoelectric, with the white LED apparent temperature rise, forward voltage, the color coordinates and color purity tends to go down. On the contrary with increasing junction temperature, the half-value wavelength and color temperature are increased accordingly.

scholarly journals LED Light Improved by an Optical Filter to Visible Solar-Like Light with High Color Rendering

Coatings ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 763
Author(s):  
Li-Siang Shen ◽  
Hsing-Yu Wu ◽  
Li-Jen Hsiao ◽  
Chih-Hsuan Shih ◽  
Jin-Cherng Hsu
Keyword(s):  
Light Emitting Diode ◽  
Multilayer Coating ◽  
Optical Filter ◽  
Deposition Process ◽  
Color Temperature ◽  
Light Sources ◽  
White Led ◽  
Easy Method ◽  
The Cost ◽  
Color Rendering

In this study, a new, cost-effective, rapid, and easy method to produce a sunlight-like D65 light source from a typical white light-emitting diode (LED) is discussed. The novelty of this method is that the emission spectrum of a typical white LED is measured first, then the reverse spectrum is used to design and fabricate a double-sided multilayer coating filter to set in front of the typical white LED. This can be verified experimentally to improve the color-rendering index of the white LED to 95.8 at the D65 color temperature. The optical thicknesses of the multilayer film are designed at a quarter wavelength. The layer-thickness errors during the deposition process are reduced due to easy monitoring with the turning-point method. By lowering both the cost and level of technology required to produce D65 light sources, in addition to the most direct consequences of increased D65 availability and affordability, the cost and level of technology required for research that heavily utilizes D65 light sources can also be lowered in turn, especially in the fields of clinical science, medicine, and related industries.

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