scholarly journals Selection of Remote Phosphor Led Packages for Improving Luminous Flux

2020 ◽  
Vol 4 (2) ◽  
pp. 118
Author(s):  
Ming Jui Chen ◽  
Hsiao-Yi Lee ◽  
Nguyen Doan Quoc Anh ◽  
Thi Phuong Loan Nguyen ◽  
Van Tho Le
Keyword(s):  
White Light ◽  
Layer Structure ◽  
Luminous Flux ◽  
White Leds ◽  
Creative Commons ◽  
Triple Layer ◽  
Study Results ◽  
Remote Phosphor ◽  
Color Rendering Index ◽  
Color Rendering

In this paper, the first issue presented and analyzed by several experiments is the influence of the distance between phosphor layers in the dual-layer and triple-layer remote package on luminous flux and color rendering property. During the simulation, it was realized that it was possible to create a suitable distance to create higher quality white light-emitting diodes (WLEDs) by adjusting the distance between the phosphor layers. According to the study results, 0.1 mm is the most reasonable distance between two phosphor layers so that the performance of the multi-chip white light LED (MCW LED) can get the best optimal effect. Through a series of experiments, it has been proved that the efficiency of the two-layer structure gives optical properties higher than the three-layer structure related to distance. The highest achievable lumen output is 0.6 mm for the triple-layer structure and 0.1 mm for dual-layer structure. Meanwhile, the color rendering index changes insignificantly when the distance increases. The triple-layer package is not practical for high-power white LEDs due to the high cost and low conversion efficiency. The dual-layer remote phosphor package with a 0.1 mm phosphorus gap is the optimal structure of WLED in improving luminous efficiency and color rendering index.  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.

scholarly journals Enhance the chromatic uniformity and luminous efficiency of WLEDs with triple-layer remote phosphor structures

2020 ◽  
Vol 10 (6) ◽  
pp. 6244
Author(s):  
Nguyen Thi Phuong Loan ◽  
Anh Tuan Le
Keyword(s):  
Layer Structure ◽  
Luminous Flux ◽  
Color Temperature ◽  
Color Quality ◽  
Important Target ◽  
Triple Layer ◽  
Color Uniformity ◽  
Remote Phosphor ◽  
Color Rendering ◽  
Better Than

The angular color uniformity (ACU) with the ability to evaluate chromatic performance of WLED has become an important target to achieve in producing higher-quality WLEDs. This paper studies the ACU enhancing effects of novel triple-phosphor configuration in lighting devices with remote phosphor structure. Moreover, the optical influences of remote phosphor structure with three phosphor layers (TL) on WLEDs properties are calculated and compared to the dual-layer (DL) one for reference. The experiments are applied to devices at 5 distinct correlated color temperature ranging from 5600-8500 K. The results presented that DL structure attains better color rendering index (CRI) than the TL one. Meanwhile, in terms of color quality scales (CQS), TL model shows higher values at all ACCTs, compared to the DL. Moreover, the luminous flux of DL configuration is lower than that of TL structure. In addition, the diversion of color temperature depicts as D-CCT in TL structure is much better than the value in DL structure, especially at high ACCT as 8500 K, which means TL is good for chromatic uniformity of high ACCTs WLEDs. These results proved that the triple-layer structure is superior and more effective to apply for acquiring the enhancement of WLEDs package.

scholarly journals Selecting a Suitable Remote Phosphor Configuration for Improving Color Quality of White Led

2019 ◽  
Vol 3 (4) ◽  
pp. 503
Author(s):  
Hsiao-Yi Lee ◽  
Phan Xuan Le ◽  
Doan Quoc Anh Nguyen
Keyword(s):  
Color Temperature ◽  
Research Results ◽  
White Leds ◽  
Creative Commons ◽  
Color Quality ◽  
Triple Layer ◽  
Color Uniformity ◽  
Remote Phosphor ◽  
Color Rendering

When compared with two conformal phosphor and in-cup phosphor structures, the remote phosphor structure has higher luminescent performance. However, it is difficult to control the color quality of the remote phosphor structure, so it has become a research target in recent years. So far, there are two remote phosphor structures used to improve color quality including dual-layer phosphor configuration and triple-layer phosphor configuration. This study suggests using those two configurations to make multi-chip white LEDs (WLEDs) that can achieve adequate values in color rendering index (CRI), color quality scale (CQS), luminous efficacy (LE) and color uniformity. WLEDs with a color temperature of 5600 K are applied. Research results show that the triple-layer phosphor configuration is superior in CRI, CQS, LE. Besides, the color deviation decreases significantly, meaning that the color homogeneity increases with the triple-layer phosphor configuration. This can be demonstrated by analyzing the scattering characteristics of phosphor classes through Mie theory, thus making the research results more reliable and valuable for producing quality WLEDs. 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.

scholarly journals Selection of a Remote Phosphor Structure for Phosphor-converted White LEDs with High Luminous Efficacy

2018 ◽  
Vol 72 ◽  
pp. 02003
Author(s):  
Long Nguyen Ngoc ◽  
Nguyen Doan Quoc Anh ◽  
Nhu Nguyen Hong ◽  
Jaroslav Zdralek ◽  
Miroslav Voznak
Keyword(s):  
Layer Structure ◽  
Luminous Flux ◽  
White Led ◽  
Luminous Efficacy ◽  
White Leds ◽  
Triple Layer ◽  
Remote Phosphor ◽  
Simulation Results ◽  
Optimal Effect ◽  
Selection Of

This study presents the influence of the distance between phosphor layers in the dual-layer and triplelayer remote package on luminous efficacy. During the simulation, it is recognized that an appropriate distance can produce higher luminous flux of the multi-chip white LED (WLEDs) through adjusting the distance between two and three phosphor layers. According to the research results, 0.1 mm is the outstanding distance between two phosphor layers so that the performance of MCW-LEDs can be accomplished the best optimal effect. In addition, the simulation results show that the dual-layer structure yielded higher optical properties than the triple – layer structure in relation to the distance.

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.

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.

Color-tunable Al6Si2O13:Eu2+,Mn2+ phosphor with high color rendering index based on energy transfer for warm white LEDs

2018 ◽  
Vol 42 (18) ◽  
pp. 15207-15214 ◽  
Author(s):  
Bo Yan ◽  
Gui-Gen Wang ◽  
Long-Fei Liu ◽  
Xin-Zhong Wang ◽  
You-Xiao Chen ◽  
...  
Keyword(s):  
Energy Transfer ◽  
White Light ◽  
White Led ◽  
Light Emitting ◽  
White Leds ◽  
Warm White Light ◽  
Color Tunable ◽  
Color Rendering Index ◽  
Color Rendering

A type of warm-white-light-emitting Al6Si2O13:Eu2+,Mn2+ phosphor with high color rendering index was synthesized for UV-excited white LED.

scholarly journals A broadband cyan-emitting Ca2LuZr2(AlO4)3:Ce3+ garnet phosphor for near-ultraviolet-pumped warm-white light-emitting diodes with an improved color rendering index

2020 ◽  
Vol 8 (3) ◽  
pp. 1095-1103 ◽  
Author(s):  
Liangling Sun ◽  
Balaji Devakumar ◽  
Jia Liang ◽  
Shaoying Wang ◽  
Qi Sun ◽  
...  
Keyword(s):  
White Light ◽  
Light Emitting Diodes ◽  
Emission Spectra ◽  
Light Emitting ◽  
White Leds ◽  
Near Ultraviolet ◽  
Warm White Light ◽  
Color Rendering Index ◽  
White Light Emitting Diodes ◽  
Color Rendering

Broadband cyan-emitting Ca2LuZr2(AlO4)3:Ce3+ garnet phosphors enabled to fill the cyan gap in the emission spectra of near-ultraviolet-pumped warm-white LEDs, thus resulting in improved color rendering index.

scholarly journals Exellent Color Quality and Luminous Flux of Wleds Using Triple-Layer Remote Phosphor Configuration

2020 ◽  
Vol 4 (1) ◽  
pp. 74
Author(s):  
Min-Feng Lai ◽  
Hsiao-Yi Lee ◽  
Doan Quoc Anh Nguyen
Keyword(s):  
Red Light ◽  
Green Light ◽  
Luminous Flux ◽  
Green Phosphor ◽  
Light Component ◽  
Research Results ◽  
White Leds ◽  
Color Quality ◽  
Triple Layer ◽  
Remote Phosphor

This study proposed a triple-layer remote phosphor (TRP) structure to improve the color and luminous flux of white LEDs (WLEDs). TRP structure consists of 3 different phosphor layers: yellow YAG:Ce3+ layer below, red CaMgSi2O6:Eu2+,Mn2+ phosphor on top and green layer Ba2Li2Si2O7:Sn2+,Mn2+  phosphor in the middle. Using red CaMgSi2O6:Eu2+,Mn2+ to control the red light component leads to increased color rendering index (CRI). Utilize the green CaMgSi2O6:Eu2+,Mn2+ phosphor to control the green light component results in the increase in luminous efficacy (LE) of WLEDs. Furthermore, when the concentration of these two phosphors increased, yellow layer concentration YAG:Ce3+ decreased to maintain average correlated color temperatures (ACCTs) in the range from 6000 K-8500K. Besides CRI and LE, color quality scale (CQS) is also analyzed through concentration control of green phosphor and red phosphor. The research results show that the higher the concentration of CaMgSi2O6:Eu2+,Mn2+, the better for CRI. In contrast, CRI decreased significantly when increasing the concentration of Ba2Li2Si2O7:Sn2+,Mn2+. Meanwhile, CQS achieve notable enhancement in the concentration range of 10% -14% CaMgSi2O6:Eu2+,Mn2+, regardless of Ba2Li2Si2O7:Sn2+,Mn2+ concentration. LE, in particular, can also increase by more than 40% along with the improvement of CRI and CQS with the reduction of the backscattered light and addition of green light. Research results are a valuable reference for producers who wish to improve the color quality and enhance the luminous flux of WLEDs. 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.

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