Efficient cerium-based sol–gel derived phosphors in different garnet matrices for light-emitting diodes

Efficiency of sol–gel derived Y3−xAl5O12:Cex3+ (YAG:Ce) and Y3−xMg2AlSi2O12:Cex3+ (YMASG:Ce) phosphors, which are prospective for application in white light emitting diodes (LED), is studied. Sets of samples containing different cerium amount x from 0.015 to 0.06 and sintered at different temperatures (1400–1550 °C) were investigated. Importance of absorption peculiarities in agglomerates of phosphor nanocrystals is demonstrated by studying the excitation wavelength dependence of quantum efficiency and by applying PL measurements in confocal mode. Emission saturation is demonstrated to occur at higher excitation intensities than those typical for operating white LEDs.

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► Emission band of novel phosphor YMASG:Ce redshifts in respect to that of YAG:Ce.
► YMASG:Ce luminescence quantum efficiency is comparable to that of YAG:Ce.
► Strong concentration quenching of YMASG:Ce luminescence efficiency is observed.
► YMASG:Ce phosphor is prospective for white LEDs with improved color rendering.