Enhancing color quality of WLEDs with dual-layer remote phosphor geometry
Usually, remote phosphor structures are beneficial in terms of flux but unfavorable in terms of color quality compared to conformal phosphor or in-cup phosphor packages. To eliminate this disadvantage, many studies have focused on increasing the chromatic quality of the remote phosphor configuration...
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doaj-bb939a36c60e458ba264897301e8faca2021-09-06T19:22:36ZengSciendoMaterials Science-Poland2083-134X2020-12-0138466767410.2478/msp-2020-0070Enhancing color quality of WLEDs with dual-layer remote phosphor geometryThat Phung Ton0Loan Nguyen Thi Phuong1Van Tho Le2Anh Nguyen Doan Quoc3Liao Hsing-Yuan4Luo Guo-Feng5Lee Hsiao-Yi6Faculty of Electronics Technology, Industrial University of Ho Chi Minh City, Ho Chi Minh City, VietnamFaculty of Fundamental 2, Posts and Telecommunications Institute of Technology, Ho Chi Minh City, VietnamInstitute of Tropical Biology, Vietnam Academy of Science and Technology, Ho Chi Minh City, VietnamFaculty of Electrical and Electronics Engineering, Ton Duc Thang University, Ho Chi Minh City, VietnamDepartment of Electrical Engineering, National Kaohsiung University of Science and Technology, Kaohsiung, TaiwanDepartment of Electrical Engineering, National Kaohsiung University of Science and Technology, Kaohsiung, TaiwanDepartment of Electrical Engineering, National Kaohsiung University of Science and Technology, Kaohsiung, TaiwanUsually, remote phosphor structures are beneficial in terms of flux but unfavorable in terms of color quality compared to conformal phosphor or in-cup phosphor packages. To eliminate this disadvantage, many studies have focused on increasing the chromatic quality of the remote phosphor configuration, which requires great efforts in improving two parameters of color: color rendering index (CRI) and color quality scale (CQS). CRI is known as the most useful quantitative method used to measure the ability of a light source to reproduce the colors of illuminated objects faithfully and naturally. Similarly, CQS is also a method of lighting quality determination and analysis, especially used as an alternative to the unsaturated CRI colors. In this paper, we proposed dual-layer remote phosphor structure as a novel method of CRI and CQS enhancement to improve WLEDs’ color quality. Five alike WLEDs but having different color temperatures in the range of 5600 K to 8500 K were applied in this study. The idea behind the study is to place a red phosphor layer SrwFxByOz:Eu2+,Sm2+ on the yellow phosphor layer YAG:Ce3+ and then determining an appropriate concentration of SrwFxByOz:Eu2+,Sm2+ added to achieve the highest color quality. The results point out that SrwFxByOz:Eu2+,Sm2+ brings great benefits to the improvement of CRI and CQS parameters. Specifically, the higher the SrwFxByOz:Eu2+,Sm2+ concentration results in the greater CRI and CQS, owning to the enriched red light components in the WLEDs. However, the flux has a tendency of dropping when SrwFxByOz:Eu2+,Sm2+ concentration rises excessively. This has been proved by using the Mie-scattering theory and the Lambert-Beer law. The results of this article are essential references for manufacturing WLEDs with higher chromatic quality.https://doi.org/10.2478/msp-2020-0070dual-layer remote phosphor geometrywledsmie-scattering theorycolor uniformityluminous flux |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
That Phung Ton Loan Nguyen Thi Phuong Van Tho Le Anh Nguyen Doan Quoc Liao Hsing-Yuan Luo Guo-Feng Lee Hsiao-Yi |
spellingShingle |
That Phung Ton Loan Nguyen Thi Phuong Van Tho Le Anh Nguyen Doan Quoc Liao Hsing-Yuan Luo Guo-Feng Lee Hsiao-Yi Enhancing color quality of WLEDs with dual-layer remote phosphor geometry Materials Science-Poland dual-layer remote phosphor geometry wleds mie-scattering theory color uniformity luminous flux |
author_facet |
That Phung Ton Loan Nguyen Thi Phuong Van Tho Le Anh Nguyen Doan Quoc Liao Hsing-Yuan Luo Guo-Feng Lee Hsiao-Yi |
author_sort |
That Phung Ton |
title |
Enhancing color quality of WLEDs with dual-layer remote phosphor geometry |
title_short |
Enhancing color quality of WLEDs with dual-layer remote phosphor geometry |
title_full |
Enhancing color quality of WLEDs with dual-layer remote phosphor geometry |
title_fullStr |
Enhancing color quality of WLEDs with dual-layer remote phosphor geometry |
title_full_unstemmed |
Enhancing color quality of WLEDs with dual-layer remote phosphor geometry |
title_sort |
enhancing color quality of wleds with dual-layer remote phosphor geometry |
publisher |
Sciendo |
series |
Materials Science-Poland |
issn |
2083-134X |
publishDate |
2020-12-01 |
description |
Usually, remote phosphor structures are beneficial in terms of flux but unfavorable in terms of color quality compared to conformal phosphor or in-cup phosphor packages. To eliminate this disadvantage, many studies have focused on increasing the chromatic quality of the remote phosphor configuration, which requires great efforts in improving two parameters of color: color rendering index (CRI) and color quality scale (CQS). CRI is known as the most useful quantitative method used to measure the ability of a light source to reproduce the colors of illuminated objects faithfully and naturally. Similarly, CQS is also a method of lighting quality determination and analysis, especially used as an alternative to the unsaturated CRI colors. In this paper, we proposed dual-layer remote phosphor structure as a novel method of CRI and CQS enhancement to improve WLEDs’ color quality. Five alike WLEDs but having different color temperatures in the range of 5600 K to 8500 K were applied in this study. The idea behind the study is to place a red phosphor layer SrwFxByOz:Eu2+,Sm2+ on the yellow phosphor layer YAG:Ce3+ and then determining an appropriate concentration of SrwFxByOz:Eu2+,Sm2+ added to achieve the highest color quality. The results point out that SrwFxByOz:Eu2+,Sm2+ brings great benefits to the improvement of CRI and CQS parameters. Specifically, the higher the SrwFxByOz:Eu2+,Sm2+ concentration results in the greater CRI and CQS, owning to the enriched red light components in the WLEDs. However, the flux has a tendency of dropping when SrwFxByOz:Eu2+,Sm2+ concentration rises excessively. This has been proved by using the Mie-scattering theory and the Lambert-Beer law. The results of this article are essential references for manufacturing WLEDs with higher chromatic quality. |
topic |
dual-layer remote phosphor geometry wleds mie-scattering theory color uniformity luminous flux |
url |
https://doi.org/10.2478/msp-2020-0070 |
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