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

To achieve further enhancement in the lighting quality of white light-emitting diodes (WLEDs), this study proposed a packaging structure with three different phosphor layers, called triple-layer remote phosphor structure. This structure can provide an overall control over the light color distribution of WLEDs. The yellow-green-emitting CaAl2O4:Mn2+ phosphor and red-emitting CaMoO4:Eu3+ phosphor are used along with the original yellow-emitting YAG:Ce3+ phosphor to fabricate the triple-layer structure. The concentration of yellow-emitting YAG:Ce3+ phosphor is required to be decreased as the concentrations of other phosphors increase to keep the predetermined correlated color temperatures. The color rendering index (CRI) and the color quality scale (CQS) are measured to reach a thorough color quality assessment for WLEDs. The color management can be achieved by adjusting the concentration of red-emitting CaMoO4:Eu3+ phosphor to enhance the red emission. In addition, adjustment of the concentration of yellow-green-emitting CaAl2O4:Mn2+ phosphor can result in higher luminous efficiency owing to its control over the green light components. Higher CRI is observed when CaMoO4:Eu3+ concentration increases, while an increase in CaAl2O4:Mn2+ phosphor leads to much lower CRI. The CQS – on the other hand – is remarkably high when the CaMoO4:Eu3+ concentration range is about 10wt%–14wt%, regardless of the proportion of the CaAl2O4:Mn2+ phosphor. Furthermore, 40% enhancement in luminous efficiency is also achieved since light scattering is minimized by the boosted green-light emission spectra. Manufacturers can take these findings as reference to fabricate high-quality WLED lights that fulfill all their requirements.
</abstract>

To achieve further enhancement in the lighting quality of white light-emitting diodes (WLEDs), this study proposed a packaging structure with three different phosphor layers, called triple-layer remote phosphor structure. This structure can provide an overall control over the light color distribution of WLEDs. The yellow-green-emitting CaAl2O4:Mn2+ phosphor and red-emitting CaMoO4:Eu3+ phosphor are used along with the original yellow-emitting YAG:Ce3+ phosphor to fabricate the triple-layer structure. The concentration of yellow-emitting YAG:Ce3+ phosphor is required to be decreased as the concentrations of other phosphors increase to keep the predetermined correlated color temperatures. The color rendering index (CRI) and the color quality scale (CQS) are measured to reach a thorough color quality assessment for WLEDs. The color management can be achieved by adjusting the concentration of red-emitting CaMoO4:Eu3+ phosphor to enhance the red emission. In addition, adjustment of the concentration of yellow-green-emitting CaAl2O4:Mn2+ phosphor can result in higher luminous efficiency owing to its control over the green light components. Higher CRI is observed when CaMoO4:Eu3+ concentration increases, while an increase in CaAl2O4:Mn2+ phosphor leads to much lower CRI. The CQS – on the other hand – is remarkably high when the CaMoO4:Eu3+ concentration range is about 10wt%–14wt%, regardless of the proportion of the CaAl2O4:Mn2+ phosphor. Furthermore, 40% enhancement in luminous efficiency is also achieved since light scattering is minimized by the boosted green-light emission spectra. Manufacturers can take these findings as reference to fabricate high-quality WLED lights that fulfill all their requirements.

Triple-layer remote phosphor structure: A potential packaging configuration to enhance both color quality and lumen efficiency of 6,000–8,500 K WLEDs

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.

To achieve further enhancement in the lighting quality of white light-emitting diodes (WLEDs), this study proposed a packaging structure with three different...

Triple-layer remote phosphor structure: A potential packaging configuration to enhance both color quality and lumen efficiency of 6,000–8,500 K WLEDs

Published Online: Feb 18, 2022

Page range: 458 - 466

Received: Apr 09, 2021

Accepted: Jun 29, 2021

DOI: https://doi.org/10.2478/msp-2021-0037

Keywords
WLEDs, CaMoO:Eu, CaAlO:Mn, luminous efficiency, color quality, remote phosphor structure, triple-layer phosphor structure

© 2021 Phan Xuan Le et al., published by Sciendo

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

Triple-layer remote phosphor structure: A potential packaging configuration to enhance both color quality and lumen efficiency of 6,000–8,500 K WLEDs

Published Online: Feb 18, 2022

Page range: 458 - 466

Received: Apr 09, 2021

Accepted: Jun 29, 2021

DOI: https://doi.org/10.2478/msp-2021-0037

KeywordsWLEDs, CaMoO:Eu, CaAlO:Mn, luminous efficiency, color quality, remote phosphor structure, triple-layer phosphor structure

© 2021 Phan Xuan Le et al., published by Sciendo

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

Keywords
WLEDs, CaMoO:Eu, CaAlO:Mn, luminous efficiency, color quality, remote phosphor structure, triple-layer phosphor structure