The Use of Y3Al5O12:Ce3+ and CaTiO3:Pr3+ in a Dual-layer Remote Phosphor Configuration Improves the Optical Efficiencies of a Phosphor-in-Glass White Light-Emitting Diode

Abstract

Although distant phosphor structure is not the best choice for color fidelity of white-light-emitting diode (W-LED) sources, it benefits the luminous flux of LED more than conformal or in-cup phosphor models. After recognizing the potential of remote phosphor structures, numerous studies have been done to overcome their drawbacks of light chromaticity. In this study, a phosphor package with two phosphor films is suggested for the W-LED. The two-layer remote phosphor structure is recognized to offer a great probability of heightened chromatic rendering parameters, including the color rending index CRI and the color quality scale CQS. The color temperature of the W-LEDs employed in this investigation is 8500 K. Placing a layer of green Y₃Al₅O₁₂:Ce³⁺ or red CaTiO₃:Pr³⁺ phosphor on top of the yellow phosphor YAG:Ce³⁺  layer will create the desired two-layered phosphor structure's form. The added phosphor CaTiO₃:Pr³⁺ concentration will then be adjusted to achieve the best color quality. The existence of CaTiO₃:Pr³⁺ increased CRI and CQS, implying that it has a significant impact on these two features. The concentration of CaTiO₃:Pr³⁺ parallel with the CRI and CQS as the red spectral component is promoted within the W-LED. In the meantime, the green phosphor Y₃Al₅O₁₂:Ce³⁺ advances the luminous flux. However, if the red CaTiO₃:Pr³⁺ and green Y₃Al₅O₁₂:Ce³⁺ phosphor concentrations are above the respective levels, it will diminish the luminous flux and color quality. According to Mie-scattering theory and Lambert- Beer's law to describe the outcome of this research. The conclusions of this study are crucial guidelines for producing better white light quality in W-LEDs.

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.