Synthesis and characterization of YAG:Ce phosphors for white LEDs

Abstract

Worldwide commercial interest in the production of cerium doped yttrium aluminium garnet (YAG:Ce) phosphors is reflected in the widespread use of white light emitting devices. Despite of the fact that YAG:Ce is considered a “cool phosphor” it is the most important in white LED technology. This article reviews the developed techniques for producing phosphors with superior photoluminescence efficiency, including solid-state reaction, sol-gel and (co)precipitation methods. Also, by co-doping with rare earth elements, a red/blue shift is reached in the spectrum. The characteristics of YAG:Ce phosphors are investigated because the properties of the phosphors are strongly influenced by the synthesis routes and the sintering temperature treatment. After the phase analysis, morphology and emission studies of the phosphors there may be seen the conditions when the transition from the amorphous phase to the crystalline phase appears, when luminescent properties are influenced by the crystalline form, purity, average size of the particles, co-doping and so on.

Tunable Eu2+ emission in KxNa1−xLuS2 phosphors for white LED application

“…However, many suffer from very low excitation efficiency in near UV part of the spectrum, see for example [22][23][24][25]. Nowadays, the garnets are probably the most widely used [26][27][28][29][30][31][32][33]. Recently, a very interesting group of sulfide-based materials has been given attention as well [34][35][36][37][38][39][40][41][42][43][44][45][46].…”

Polymer-Oxide Composites: Toward New Optical Materials

“…This is a photoluminescence coating (PLC) of UV or blue LEDs for white LEDs creation on their base. Indeed, it is common knowledge that most commercially attractive WLEDs contain the PLC made on the base of yttrium aluminum garnet (YAG) doped with cerium, Y 3 Al 5 O 12 :Ce 3+ (YAG:Ce), dispersed in polymer (silicone) matrix [25,26]. Similarly, polymer matrix (polymethylmethacrylate or polyvinylacetate, etc.)…”

Massive red shift of Ce3+in Y3Al5O12incorporating super-high content of Ce

“…10,11 YAG:Ce has a garnet structure, A 3 B 2 C 3 O 12 , where Y 3+ is in dodecahedral site (A) and Al 3+ is both in octahedral (B) and tetrahedral sites (C). 12 These cations (Y 3+ and Al 3+ ) can be replaced by ions with different sizes, which allow the exibility of crystal structure and optimization of luminescence properties. Variation of photoluminescent property by the substitution of Y and Al sites has been extensively studied.…”