Spectrum regulation of YAG:Ce/YAG:Cr/YAG:Pr phosphor ceramics with barcode structure prepared by tape casting

Abstract

AbstractYAG:Ce/YAG:Cr/YAG:Pr composite phosphor ceramics with barcode structure were prepared by tape casting combined with the solid‐state reaction method. This structure provides a convenient and effective method for regulating the optical parameters such as luminous efficacy (LE), color rendering, and correlated color temperature (CCT) of white light‐emitting diodes/laser diodes (LEDs/LDs). For the sample with a thickness ratio of 6:6:6 for YAG:Ce, YAG:Cr, and YAG:Pr, the in‐line transmittance reaches 60% at 800 nm, and it shows a good optical performance with the LE of 106 lm/W, the color gamut (Rg) of 77, the color fidelity index (Rf) of 86, and the CCT of 7642 K. The electroluminescence spectra and color coordinates can be adjusted by changing the ratio of each component in the composite ceramic and the thickness of the ceramic because the tape casting method allows precise control of the thickness of each ceramic layer. The high tunability provides more freedom in the performance design of composite phosphor ceramics and makes them the most promising candidate for high brightness white LEDs/LDs.