scholarly journals The effect green YF3:ER3+,YB3+ phosphor on luminous flux and color quality of multi-chip white light-emitting diodes

2021 ◽  
Vol 11 (6) ◽  
pp. 4810
Author(s):  
My Hanh Nguyen Thi ◽  
Nguyen Thi Phuong Loan ◽  
Thuc Minh Bui ◽  
Anh Tuan Le
Keyword(s):  
White Light ◽  
Light Output ◽  
Luminous Flux ◽  
Green Phosphor ◽  
Light Emitting ◽  
Color Quality ◽  
Quality Scale ◽  
White Light Emitting Diodes ◽  
New Generation

The purpose of this paper is to demonstrate the advantages of the green phosphor YF<sub>3</sub>:Er<sup>3+</sup>,Yb<sup>3+ </sup>combined with multi-chip package to the enhancement of lighting efficiency of modern WLEDs. In an effort to improve the quality of WLEDs and create a new generation of lighting device, green phosphor YF<sub>3</sub>:Er<sup>3+</sup>,Yb<sup>3+ </sup>is added into the phosphor compounding of the WLED package to improve the color quality and lighting capacity. Through experiments, WLEDs with YF<sub>3</sub>:Er<sup>3+</sup>,Yb<sup>3+ </sup>green phosphor has shown improved results in lighting performance specifically in color homogeneity and light output of WLEDs in the ACCT range from 5600-7000 K. However, the color quality scale (CQS) declines gradually. Therefore, if the appropriate concentration and size of YF<sub>3</sub>:Er<sup>3+</sup>,Yb<sup>3+</sup> are determined, the performance of MCW-LEDs will be enhanced and become more stable.

Excellent Color Quality of White-Light-Emitting Diodes by Embedding Quantum Dots in Polymers Material

2016 ◽  
Vol 22 (1) ◽  
pp. 35-41 ◽  
Author(s):  
Huang-Yu Lin ◽  
Sheng-Wen Wang ◽  
Chien-Chung Lin ◽  
Kuo-Ju Chen ◽  
Hau-Vei Han ◽  
...  
Keyword(s):  
Quantum Dots ◽  
White Light ◽  
Light Emitting Diodes ◽  
Light Emitting ◽  
Color Quality ◽  
White Light Emitting Diodes ◽  
Excellent Color

scholarly journals Excellent Luminous Efficacy and Color Homogeneity of White Light-Emitting Diodes with YPO4:Ce3+:Tb3+ Phosphor

2018 ◽  
Vol 72 ◽  
pp. 02002
Author(s):  
Vo Phu Thoai ◽  
Nguyen Doan Quoc Anh
Keyword(s):  
White Light ◽  
Light Emitting Diodes ◽  
White Led ◽  
Gradual Decline ◽  
Luminous Efficacy ◽  
Light Emitting ◽  
Color Quality ◽  
Quality Scale ◽  
Color Uniformity ◽  
White Light Emitting Diodes

In this paper, we focus on researching the method, which the color homogeneity and the lumen output of multi-chip white LED lamps (MCW-LEDs) need to support for increasing the efficiency. The successful results can be achieved by mixing the green YPO4:Ce3+:Tb3+ phosphor with their phosphor compounding. Through experiment results, we assert that the MCW-LEDs can achieve the significant consequence in performance by following that method and it is also again confirmed that when the concentration of YPO4:Ce3+:Tb3+ has tendency to increase, which impulse the development of the color uniformity and the luminous efficacy of MCW-LEDs with average correlated color temperatures (CCT) of 8500 K, while the color quality scale shows signs of gradual decline. It is not difficult to gain incredible presentation of MCW-LEDs if we are clever in choosing the suitable concentration and size of YPO4:Ce3+:Tb3+.

scholarly journals Enhancing Luminous Efficacy of White Led Lamp Using Ca2MgSi2O7:Eu2+ Phosphor

2018 ◽  
Vol 2 (2) ◽  
pp. 103
Author(s):  
Doan Quoc Anh Nguyen ◽  
Thi Phuong Thao Nguyen ◽  
Postava Kamil
Keyword(s):  
Rapid Development ◽  
Essential Element ◽  
Luminous Flux ◽  
Luminous Efficacy ◽  
Light Emitting ◽  
White Leds ◽  
Creative Commons ◽  
Quality Scale ◽  
White Light Emitting Diodes

Along with the rapid development of science and technology in today's society, lighting technology, especially white light-emitting diodes (WLEDs), has become a critical and essential element in almost every field of our daily life. Therefore, the enhancement of luminous efficiency has become an important objective in the production of white LEDs to serve the needs of customers. This paper presents the influence of Ca2MgSi2O7:Eu2+ green luminescent phosphor on the light quality of WLEDs. In this work, the green-emitting Ca2MgSi2O7:Eu2+ phosphor is added into the in-cup phosphor configuration, which leads to the varying of the scattering property of this compounding. This is proved through the scattering coefficient from Mie-theory. Besides, the color quality scale which is called CQS index of WLEDs is also verified. The achieved results indicate that the luminous efficacy increases significantly if the Ca2MgSi2O7:Eu2+ concentration is varied. The smaller the Ca2MgSi2O7:Eu2+ size is used, the higher the luminous flux is obtained. However, the CQS can decrease if Ca2MgSi2O7:Eu2+ concentration is adjusted in another direction. Therefore, it is vital to select a suitable concentration and size of Ca2MgSi2O7:Eu2+ for enhancing the luminous efficacy of WLEDs, and the benet of this phosphor in creating white WLED packages is a potential solution for developing LED illumination technology.  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 Using CaCO3-doped package to improve correlated color temperature uniformity of white light-emitting diodes

2021 ◽  
Vol 11 (6) ◽  
pp. 4817
Author(s):  
My Hanh Nguyen Thi ◽  
Nguyen Thi Phuong Loan ◽  
Thuc Minh Bui ◽  
Hoang Van Ngoc
Keyword(s):  
White Light ◽  
Light Emitting Diode ◽  
Luminous Flux ◽  
Color Temperature ◽  
Resin Matrix ◽  
Light Emitting ◽  
Color Quality ◽  
Color Uniformity ◽  
Stability Enhancement ◽  
White Light Emitting Diodes

<span>The white light-emitting diode (WLED) has been the most advance lighting method currently, however, the fabrication process of this configuration still has drawbacks which negatively affect its color quality. This research was conducted to provide a method for WLED’s lighting output enhancement. Since CaCO<sub>3</sub> particles are excellent for thermal stability enhancement, especially when being combined with an adhesive substance, we decided to integrate CO<sub>3</sub> particles into resin matrix such as melamine formaldehyde (MF) and investigate their influences on the optical properties, including color uniformity and lumen output, of the WLED. The results showed that CaCO3 and MF resin are beneficial to the light scattering efficiency, which results in higher luminous flux and chromatic quality for WLED packages. In addition to that, the appropriate amounts of MF resin and CaCO<sub>3</sub> for reaching the best lumen efficiency and color quality are figured out at 1% and 10%, respectively. Moreover, another advantage of using MF resin and CaCO<sub>3</sub> for fabricating WLEDs is cost effectiveness. Hence, it has turned out that CaCO<sub>3</sub> and MF resins can be potential materials for next high-quality WLED generations.</span>

A novel green phosphor LaMgAl11O19:Ho3+ for near-UV/blue light-pumped white light-emitting diodes

2015 ◽  
Vol 618 ◽  
pp. 182-185 ◽  
Author(s):  
Xin Min ◽  
Minghao Fang ◽  
Zhaohui Huang ◽  
Hao Liu ◽  
Yan’gai Liu ◽  
...  
Keyword(s):  
Blue Light ◽  
White Light ◽  
Light Emitting Diodes ◽  
Green Phosphor ◽  
Light Emitting ◽  
White Light Emitting Diodes

scholarly journals (Y,Gd)BO3:Eu red phosphor for dual-layer phosphor structure to enhance the optical performance of white light-emitting diodes

2021 ◽  
Vol 10 (4) ◽  
pp. 1930-1935
Author(s):  
Phan Xuan Le ◽  
Le Hung Tien
Keyword(s):  
White Light ◽  
Light Emitting Diodes ◽  
Red Light ◽  
Phosphor Layer ◽  
Light Emitting ◽  
Conformal Coating ◽  
Color Quality ◽  
Remote Phosphor ◽  
White Light Emitting Diodes ◽  
Color Rendering

Among the structures using for fabricating white light-emitting diodes (WLEDs) such as the conformal coating or in-cup geometries, the remote phosphor structure gives the highest luminous efficacy. However, in terms of color quality, its performance is not as good as the others. The red-light compensation has been reported as the effective solution for enhancing the color quality of WLEDs. Hence, this study adopted the idea and applied to the dual-layer phosphor structure. The phosphor used to boost the red color in light formation is (Y,Gd)BO3:Eu particle. The dual-layer remote phosphor structure was simulated with the red (Y,Gd)BO3:Eu phosphor layer above the original yellow phosphor YAG:Ce3+ one. The WLEDs with different correlated color temperatures of 5600 K, 6600 K and 7700K were experimented. Mie-theory and Lambert-Beer law were applied to examine the results. The growth in color rendering index (CRI) and color quality scale (CQS) with the increase of (Y,Gd)BO3:Eu phosphor concentration was observed. Nevertheless, the lumen efficacy would be degraded if the concentration was over a certain number. The information provided in this article is useful for the development of high-power WLED production with greater color quality.

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