<abstract xmlns="http://www.w3.org/1999/xhtml">

<p>Angular color distribution uniformity has been one of the most relevant properties in the development of white light-emitting diodes (WLEDs), since color consistency and uniformity are crucial factors in quality evaluation of a WLED. Here, particularly considering the need to overcome the poor chromaticity usually associated with WLED, we introduce a new design for the remote-phosphor package, namely a three-layered or triple-layer (TL) phosphor structure. Using three phosphor layers in packaging a WLED can result in higher color quality and luminous efficacy, compared to the double-layer (DL) configuration. In the present study, the results of using three remote phosphor layers indicate that although the structure using three layers has a lower color rendering index, the color quality scale is better than that available from the package with two layers. Additionally, the color-deviation values in the TL structure are smaller than in the dual-layer one, especially at high color temperatures (7,700 K and 8,500 K). Besides, in comparison with the DL model, the TL package increases the luminous flux by 1.4%–2%. Therefore, the TL remote phosphor structure possesses the greatest potential in enhancing the WLED quality.</p>
</abstract>

Angular color distribution uniformity has been one of the most relevant properties in the development of white light-emitting diodes (WLEDs), since color consistency and uniformity are crucial factors in quality evaluation of a WLED. Here, particularly considering the need to overcome the poor chromaticity usually associated with WLED, we introduce a new design for the remote-phosphor package, namely a three-layered or triple-layer (TL) phosphor structure. Using three phosphor layers in packaging a WLED can result in higher color quality and luminous efficacy, compared to the double-layer (DL) configuration. In the present study, the results of using three remote phosphor layers indicate that although the structure using three layers has a lower color rendering index, the color quality scale is better than that available from the package with two layers. Additionally, the color-deviation values in the TL structure are smaller than in the dual-layer one, especially at high color temperatures (7,700 K and 8,500 K). Besides, in comparison with the DL model, the TL package increases the luminous flux by 1.4%–2%. Therefore, the TL remote phosphor structure possesses the greatest potential in enhancing the WLED quality.

Better color distribution uniformity and higher luminous intensity for LED by using a three-layered remote phosphor structure

Faculty of Electrical and Electronics Engineering

National Kaohsiung University of Science and Technology

Materials Science-Poland

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Angular color distribution uniformity has been one of the most relevant properties in the development of white light-emitting diodes (WLEDs), since color...

Ingredients	Mole (%)	By weight (g)
La₂O₃	95 (of La)	155
Eu₂O₃	5 (of Eu)	8.8
Li₂CO₃	101 (of Li)	37.4

Ingredients	Mole (%)	By weight (g)
ZnO	90	73.2
MgF₂	5	3.1
MnCO₃	5	5.8
GeO₂	55	57.5

Better color distribution uniformity and higher luminous intensity for LED by using a three-layered remote phosphor structure

Publié en ligne: 12 juin 2022

Pages: 60 - 67

Reçu: 19 mai 2021

Accepté: 23 sept. 2021

DOI: https://doi.org/10.2478/msp-2022-0010

Mots clés
WLEDs, luminous efficacy, color uniformity, remote phosphor structure, three-layered remote phosphor structure

© 2022 Nguyen Thi Phuong Loan et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Fig. 1

Fig. 2

Fig. 3

Fig. 4

Fig. 5

Fig. 6

Fig. 7

The red phosphor LiLaO2:Eu3+ composition

The green phosphor Zn2GeO4:Mn2+ composition

Better color distribution uniformity and higher luminous intensity for LED by using a three-layered remote phosphor structure

Publié en ligne: 12 juin 2022

Pages: 60 - 67

Reçu: 19 mai 2021

Accepté: 23 sept. 2021

DOI: https://doi.org/10.2478/msp-2022-0010

Mots clésWLEDs, luminous efficacy, color uniformity, remote phosphor structure, three-layered remote phosphor structure

© 2022 Nguyen Thi Phuong Loan et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Fig. 1

Fig. 2

Fig. 3

Fig. 4

Fig. 5

Fig. 6

Fig. 7

The red phosphor LiLaO2:Eu3+ composition

The green phosphor Zn2GeO4:Mn2+ composition

Mots clés
WLEDs, luminous efficacy, color uniformity, remote phosphor structure, three-layered remote phosphor structure