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>

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.

scholarly journals Enhancement of color quality and luminous flux for remote-phosphor LEDs with red-emitting CaMgSi2O6:Eu2+,Mn2+

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Guo-Feng Luo ◽  
Nguyen Thi Phuong Loan ◽  
Le Van Tho ◽  
Nguyen Doan Quoc Anh ◽  
Hsiao-Yi Lee
Keyword(s):  
Mie Scattering ◽  
Luminous Flux ◽  
Color Temperature ◽  
Optical Efficiency ◽  
White Leds ◽  
Color Quality ◽  
Quality Scale ◽  
Color Uniformity ◽  
Remote Phosphor ◽  
Color Rendering

AbstractSiO2 particles and red-emitting CaMgSi2O6:Eu2+,Mn2+ phosphor have been added into a yellow phosphor compound YAG:Ce3+ to enhance the optical efficiency of white light LEDs whose average correlated color temperature (CCT) is in the range of 5600 K ÷ 8500 K. It was observed that altering CaMgSi2O6:Eu2+,Mn2+ concentration from 2 % to 30 % while maintaining 5 % of the SiO2 strongly influenced the color rendering index (CRI), color quality scale (CQS), and lumen efficiency of the compound. Besides, through the application of Monte Carlo simulation and Mie-scattering theory, it was possible to improve the optical properties by CaMgSi2O6:Eu2+,Mn2+ and SiO2 addition. The results provided a practical approach to achieve higher luminous efficiency and better color uniformity in remote-phosphor white LEDs (RP-WLEDs).

scholarly journals Increasing Optical Performance of the 7000 K, 8500 K Remote Packaging WLEDs by the Red-emitting α-SrO·3B2O3:Sm2+ Conversion Phosphor

2018 ◽  
Vol 2 (1) ◽  
pp. 55
Author(s):  
Hoang Quang Minh Tran ◽  
Huu Khanh Nhan Nguyen ◽  
Hsiao-Yi Lee
Keyword(s):  
Luminous Flux ◽  
Color Temperature ◽  
Optical Performance ◽  
White Leds ◽  
Creative Commons ◽  
Color Quality ◽  
Quality Scale ◽  
Color Uniformity ◽  
Color Rendering ◽  
Open Access Article

In this paper, by mixing the red-emitting α-SrO·3B2O3:Sm2+ conversion phosphor to yellow-emitting YAG:Ce phosphor compound, an innovative recommendation for increasing optical performance of white LEDs (WLEDs) with remote packaging, which has an average correlated color temperature (CCT) of 700K and 8500K, is proposed and demonstrated. By varying α-SrO·3B2O3:Sm2+ concentration from 2% to 24 %, the obtained results indicated that color uniformity, color rendering index (CRI), color quality scale (CQS), and luminous flux could be improved significantly. The results demonstrated a prospective recommendation for manufacturing remote packaging phosphor 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 Photoluminescence tuning of Ca8−xSrxMgGd(PO4)7:Eu2+,yMn2+ phosphors for applications in white LEDs with excellent color rendering index

RSC Advances ◽  
2017 ◽  
Vol 7 (31) ◽  
pp. 19223-19230 ◽  
Author(s):  
Jiaqi Long ◽  
Yuzhen Wang ◽  
Chaoyang Ma ◽  
Xuanyi Yuan ◽  
Wenfeng Dong ◽  
...  
Keyword(s):  
Solid State ◽  
Solid State Reaction ◽  
White Leds ◽  
Color Rendering Index ◽  
Yellow Orange ◽  
Color Rendering ◽  
Excellent Color

Two series of novel phosphors of green-yellow emitting Ca8−xSrxMgGd(PO4)7:Eu2+ and yellow-orange emitting Sr8MgGd(PO4)7:Eu2+,yMn2+ were successfully synthesized by a solid-state reaction.

scholarly journals Improving color uniformity and color rending index of remote-phosphor packaging white LEDs by co-doping SiO2 and Sr2Si5N8:Eu2+ particles

2018 ◽  
Vol 36 (3) ◽  
pp. 370-374 ◽  
Author(s):  
Tran Hoang Quang Minh ◽  
Nguyen Huu Khanh Nhan ◽  
Nguyen Doan Quoc Anh ◽  
Tran Thanh Nam ◽  
Hsiao-Yi Lee
Keyword(s):  
High Efficiency ◽  
Fast Response ◽  
New Approach ◽  
White Leds ◽  
Co Doping ◽  
Color Uniformity ◽  
Remote Phosphor ◽  
Long Lifetime ◽  
Color Rendering ◽  
Near Future

AbstractBased on some advantageous properties, such as fast response time, environment friendliness, small size, long lifetime, and high efficiency, white LEDs are increasingly used in common illumination applications. In this research, by co-doping of redemitting Sr2Si5N8:Eu2+ phosphor and adding SiO2 particles to yellow-emitting YAG:Ce phosphor compounds, a new approach for improving color uniformity and color rending index of remote-phosphor structure white LEDs is proposed and demonstrated. The obtained results clearly indicate that the color rendering index (CRI) and color uniformity (ΔCCT) significantly depend on Sr2Si5N8:Eu2+ concentration. The results provide a potential practical solution for manufacturing remote-phosphor white LEDs (RP-WLEDs) in the near future.

scholarly journals Improving color quality and luminous flux of white LED utilizing triple-layer remote phosphor structure

2020 ◽  
Vol 10 (5) ◽  
pp. 5168
Author(s):  
Nguyen Thi Phuong Loan ◽  
Nguyen Doan Quoc Anh
Keyword(s):  
Light Quality ◽  
Mie Theory ◽  
Luminous Flux ◽  
Luminous Efficiency ◽  
White Led ◽  
Color Quality ◽  
Triple Layer ◽  
Quality Scale ◽  
Color Uniformity ◽  
Color Rendering

In this manuscript, we presented a research that enhance the performance of WLED using the multi-phosphor configuration. The phosphor layers in the research are separated from each other to achieved better luminous efficiency, however, it makes controlling color light quality more complex. Another issue is finding out the whether two layers of phosphor or three layers of phosphor is better in improving color quality. The research addressed this issue by analyzing the optical aspects of the respective WLEDs that employ these structure. The studied aspects are quality indicators such as luminous efficacy (LE), and color uniformity, color rendering index (CRI), color quality scale (CQS). The results of the experiments in this research, which come from the employment of WLEDs with 2 color temperatures 5600 K and 8500, suggest that WLED with three phosphor layers is better in CRI, CQS, LE. This type of phosphor structure also limits the color deviation significantly, thus, improves the color uniformity. This results is verifies with Mie theory, therefore, can be applied as reference or guideline for production of better WLEDs

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.

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