Enhanced Color Rendering and Color Uniformity of PiG Based WLEDs by Using Red Phosphor Lens

2021 ◽  
pp. 1-1
Author(s):  
Jinxiang Chen ◽  
Zhuang Tian ◽  
Qing Wang ◽  
Jiaxin Liu ◽  
Yun Mou
Keyword(s):  
Red Phosphor ◽  
Color Uniformity ◽  
Color Rendering

A red phosphor BaTiF6:Mn4+: reaction mechanism, microstructures, optical properties, and applications for white LEDs

2014 ◽  
Vol 43 (25) ◽  
pp. 9414-9418 ◽  
Author(s):  
Xianyu Jiang ◽  
Zhen Chen ◽  
Shaoming Huang ◽  
Jiaguo Wang ◽  
Yuexiao Pan
Keyword(s):  
Optical Properties ◽  
Reaction Mechanism ◽  
White Light ◽  
Red Phosphor ◽  
White Leds ◽  
Red Phosphors ◽  
Warm White Light ◽  
Color Rendering Index ◽  
Color Rendering

Red phosphors BaTiF6:Mn4+ were obtained by etching Ti(OC4H9)4 and TiO2 with BaF2 in HF and a KMnO4 solution. The WLED fabricated with BaTiF6:Mn4+ exhibits a “warm” white light with a color rendering index of 93.13.

Optimized photoluminescence of red phosphor K2TiF6:Mn4+synthesized at room temperature and its formation mechanism

2015 ◽  
Vol 3 (9) ◽  
pp. 1935-1941 ◽  
Author(s):  
Lifen Lv ◽  
Zhen Chen ◽  
Guokui Liu ◽  
Shaoming Huang ◽  
Yuexiao Pan
Keyword(s):  
Formation Mechanism ◽  
Luminescence Intensity ◽  
Room Temperature ◽  
Synthetic Process ◽  
Red Phosphor ◽  
White Leds ◽  
Red Phosphors ◽  
Color Rendering

The formation mechanism for red phosphors K2TiF6:Mn4+synthesized at room temperature has been discussed. The luminescence intensity has been improved by optimizing the synthetic process. Encapsulation of the red phosphor K2TiF6:Mn4+with YAG:Ce on a GaN layer produces “warm” white LEDs with color rendering 86 at 3251 K.

A Promising Energy-Saving and Environmental-Friendly Lighting Device: High CRI White LED with Phosphor Materials

2016 ◽  
Vol 848 ◽  
pp. 446-453
Author(s):  
Sheng Liu ◽  
Bei Ying Zhou ◽  
Shi Jia Gu ◽  
Lian Jun Wang ◽  
Wan Jiang ◽  
...  
Keyword(s):  
Environmental Scanning Electron Microscopy ◽  
Luminescence Spectra ◽  
Environmental Scanning ◽  
X Ray Diffraction ◽  
Green Phosphor ◽  
Red Phosphor ◽  
White Leds ◽  
Phase Surface ◽  
Color Rendering ◽  
Fluorescence Spectrometer

Two kinds of commercial LED phosphors (green phosphor LuAG:Ce3+ and red phosphor CaAlSiN3:Eu2+) with polymethyl methacrylate (PMMA) powders were mixed to prepare film phosphors with tunable emission peak in photoluminescence spectrum by flat vulcanizing machine under the temperature of 170 oC and pressure of 2 MPa. The physical phase, surface morphology, transmittance, luminescence spectra of samples were characterized by means of X-ray diffraction (XRD), Environmental scanning electron microscopy (ESEM), Ultraviolet-Visible (UV-Vis) spectrophotometry and Fluorescence spectrometer. The results show that the film phosphors phase was consistent with raw phosphors, phosphor particles were uniformly distributed, and fluorescence spectra with different proportions of phosphors in different position can be adjusted. Tested by HSP 3000 spectrum analyzer, the white LEDs fabricated by blue chip and composite film phosphor containing 5 wt% green phosphor and 1.5 wt.% red phosphor, which refers to the remote excitation technique, possessed color coordinate of (0.3715, 0.3280) and color rendering index (CRI) of 87 when it was driven at power of 36 V/140 mA, reaching the international advanced level.

scholarly journals Triple-layer remote phosphor structure: a novel option for the enhancement of WLEDs’ color quality and luminous flux

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
My Hanh Nguyen Thi ◽  
Phung Ton That ◽  
Nguyen Doan Quoc Anh ◽  
Tran Thanh Trang
Keyword(s):  
Performance Enhancement ◽  
Light Output ◽  
Luminous Flux ◽  
White Leds ◽  
Color Quality ◽  
Quality Scale ◽  
Color Uniformity ◽  
Remote Phosphor ◽  
Research Findings ◽  
Color Rendering

Abstract The remote phosphor as a lighting structure has outstanding luminous efficiency compared to other options, such as conformal or in-cup. However, the lack of uniformity in distributed color has prevented remote phosphor from wider development. The answer to the chromatic performance enhancement that has been suggested by numerous researchers is the multi-layer configuration with two or three different types of chromatic phosphor. The research purpose is to select the best configuration for multi-chip white LEDs (WLEDs) to achieve optimal results in color quality scale (CQS), color rendering index (CRI), light output and color homogeneity. WLEDs mentioned in this paper have two distinct color temperatures, 6600 K and 7700 K. Experimental results show that the remote phosphor structure with three phosphor layers is superior in terms of color rendering, chromatic performance, and emitted light. The deviation of correlated color measured in this structure is also low, which means that the color uniformity is greatly enhanced in this multi-layer lighting structure. This result can be demonstrated by analyzing the scattering characteristics of the phosphoric layers using the Mie theory. The research findings have proven the effectiveness of the multi-phosphor configuration and can serve as a guideline to fabricate WLEDs with better performance.

Red Phosphor Rb2NbOF5:Mn4+ for Warm White Light-Emitting Diodes with a High Color-Rendering Index

2018 ◽  
Vol 58 (1) ◽  
pp. 456-461 ◽  
Author(s):  
Zhengliang Wang ◽  
Zhiyu Yang ◽  
Zhaofeng Yang ◽  
Qianwen Wei ◽  
Qiang Zhou ◽  
...  
Keyword(s):  
White Light ◽  
Light Emitting Diodes ◽  
Red Phosphor ◽  
Light Emitting ◽  
Warm White Light ◽  
Color Rendering Index ◽  
White Light Emitting Diodes ◽  
Color Rendering

scholarly journals Warm-white light-emitting diode with high color rendering index fabricated by combining trichromatic InGaN emitter with single red phosphor

2015 ◽  
Vol 23 (7) ◽  
pp. A232 ◽  
Author(s):  
Jinn-Kong Sheu ◽  
Fu-Bang Chen ◽  
Yen-Chin Wang ◽  
Chih-Chiang Chang ◽  
Shih-Hsien Huang ◽  
...  
Keyword(s):  
White Light ◽  
Light Emitting Diode ◽  
Red Phosphor ◽  
Light Emitting ◽  
Warm White Light ◽  
Color Rendering Index ◽  
Color Rendering

A NEW RED PHOSPHOR OF THE Mn ACTIVATED NON-STOICHIOMETRIC STRONTIUM ALUMINATE 3SrO•5Al2O3 FOR HIGH COLOR RENDERING WHITE LEDS

2013 ◽  
Vol 06 (03) ◽  
pp. 1350028 ◽  
Author(s):  
LEI CHEN ◽  
YAO ZHANG ◽  
FAYONG LIU ◽  
XIAORONG DENG ◽  
SHAOCHAN XUE ◽  
...  
Keyword(s):  
Dipole Interaction ◽  
Critical Distance ◽  
Sem Analysis ◽  
Strontium Aluminate ◽  
Red Phosphor ◽  
Light Emitting ◽  
White Leds ◽  
Warm White Light ◽  
White Light Emitting Diodes ◽  
Color Rendering

A new red phosphor of strontium aluminate activated by Mn4+ was developed for high color rendering and warm white light-emitting diodes. The phosphor composition and conditions for synthesis were optimized through solid-state reaction. Meanwhile, the structure and morphology were investigated with XRD and SEM analysis. The results show that the 3SrO•5Al2O3 activated by 0.0005 M Mn fired at 1300°C in air ambient by adopting 2.5 wt.% AlF3 as flux exhibits most efficient luminescence. A white LED device prototype with CIE (0.3291, 0.3571), CCT 5639 K, CRI Ra 92.6, and efficacy 63 lm/W driven at 20 mA has been packaged by pre-coating the red phosphor combined with a yellow one Y3Al5O12:Ce3+ on a blue InGaN chip. The analysis of critical distance and luminescence quench reveal that the mechanism of energy transfer for luminescence is through dipole–dipole interaction.

Optical and Color Properties of Green and Red Phosphor Mixtures Doped into Hybrid Sol-Gel Matrix to Generate White Light

2016 ◽  
Vol 1133 ◽  
pp. 419-423 ◽  
Author(s):  
Nurul Huda Yusoff ◽  
Wedianti Shualdi ◽  
Nik Mohd Azmi Nik Abdul Aziz ◽  
Wan Mohammed Nazrul Wan Jaafar
Keyword(s):  
White Light ◽  
Sol Gel ◽  
Color Temperature ◽  
Integrating Sphere ◽  
Green Phosphor ◽  
Red Phosphor ◽  
Color Properties ◽  
Uv Led ◽  
Heat Treated ◽  
Color Rendering

Eu (tta)3phen and Tb (4DBBA)3TPPO were synthesized as red and green phosphor for generating white light under the excitation of UV LED. The phosphor materials were doped into hybrid sol-gel (VTES:TEOS) matrix with different ratio of 1:8, 1:16, 1:25, 1:30, 1:40 and 1:50. The samples were fabricated as thick films by drop-casting and heat treated at 60°C overnight. Photoluminescence spectra were measured using spectrafluorometer system. Measurement of color properties such as color rendering index (CRI), color temperature and Commission Internationale de L’Eclairge coordinates were recorded by exciting the samples using a 380nm UV LED and focused the generated light into an integrating sphere. Based on the results, the mix ratio of 1:40 produce the nearest coordinate within the white color region with color temperature around 4100K to 4200K.

scholarly journals Using Sr[Mg3SiN4]Eu2+ phosphor for enhancing color uniformity and luminous efficacy of the 7000 K IPP-WLEDs

2020 ◽  
Vol 17 (1) ◽  
pp. 126
Author(s):  
Van-Duc Phan ◽  
Phu Tran Tin ◽  
Minh Tran ◽  
Tran Thanh Trang
Keyword(s):  
Solid State ◽  
Luminescent Materials ◽  
White Leds ◽  
Color Quality ◽  
Quality Scale ◽  
Color Uniformity ◽  
Color Rendering Index ◽  
Potential Applications ◽  
Color Rendering ◽  
Near Future

<p class="TextBody">As a novel class of inorganic phosphors, oxynitride and nitride luminescent materials have received considerable attention because of their potential applications in solid-state lightings and displays. In this paper, we built the simulation model of the 7000 K in-cup phosphor packaging white LEDs (IPP-WLEDs) by using the Light Tools software. After that, the effect of the Sr[Mg3SiN4]Eu2+ phosphor particle’s size on the lighting performance in term of CCT Deviation (D-CCT), Color Rendering Index (CRI), Color Quality Scale (CQS), and Lumen Output (LO) is analyzed and investigated. In addition, the scattering processes in the phosphor layers of the 7000 K IPP_WLEDs is derived using Mat Lab software. From the research results, we can state that the phosphor size significantly effects on the lighting performance of the 7000K IPP_WLEDs. It can be seen that Sr[Mg3SiN4]Eu2+ phosphor can be considered as a novel solution for improving the lighting performance of the WLEDs in the near future.</p>

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