Color tuning of Lu3Al5O12:Dy3+ ceramic-based white light-emitting phosphors via Yb incorporation

Transparent Lu3Al5O12:Dy3+ ceramics were fabricated for UV-pumped white light-emitting diodes (WLEDs) via solid-state sintering under vacuum. The color chromaticity of the ceramic-based phosphors were tuned by tailoring the Dy3+ concentration and incorporating Yb into the crystal lattice to form (Lu, Yb)3Al5O12:Dy3+ solid solutions. Phase composition, microstructure, optical and photoluminescence properties of the ceramics were investigated in detail by X-ray diffraction (XRD), Scanning electron microscopy (SEM), UV-vis-NIR spectrometer and fluorescence spectrophotometer, respectively. White light can be obtained by combining the UV-chip and the structure/property-optimized ceramic phosphors. The color hue was tuned from (0.4107, 0.4037) to (0.3647, 0.3299) with the increasing Yb content from 0 to 0.5 substituting Lu sites in the garnet structure. The (Lu0.5Yb0.5)3Al5O12: 0.01Dy3+ ceramic-based phosphor showed a relative low correlated color temperature of 4137 K. The decrease in PL intensities with Yb incorporation was also discussed via microstructure and fluorescence lifetime characterizations.