Preparation and luminescence properties of YAG:Ce phosphor for white LED application via a vacuum sintering method

Abstract

010 62517887 YAG:Ce phosphors are synthesized by the vacuum sintering method, and their crystal structure, luminescence properties, and X-ray photoelectron spectroscopy are discussed. The synthesized temperature of pure YAG phase is reduced by vacuum sintering. As-synthesized YAG:Ce phosphors show a smaller average size of about 1 mm due to the fine starting materials, low sintering temperature, and the absence of flux. It is found that samples synthesized by the vacuum sintering method show stronger emission intensity and higher optimized Ce 3þ -doping concentration. In addition, white light-emitting diodes (LEDs) with improved color-rendering properties are obtained by using modified Pr 3þ -doped YAG:Ce phosphors.

Stable, Heat-Conducting Phosphor Composites for High-Power Laser Lighting

“…29 It is therefore possible that the addition of α-Al For transparent Ce:YAG ceramics, the quantum efficiency of the transparent ceramics were reported to be lower than Ce:YAG powder due to waveguiding and backward emission losses. 38 In translucent or scattering Ce:YAG ceramics however, pores introduce scattering and can be controlled by tuning both the pore size and the prevalence of pores. 39 This scattering can overcome light trapping effects of the high index (n=1.85 at 450 nm) in Ce:YAG.…”

“…For transparent Ce:YAG ceramics, the quantum efficiency of the transparent ceramics was reported to be lower than that of Ce:YAG powder due to waveguiding and backward emission losses . In translucent or scattering Ce:YAG ceramics, however, pores introduce scattering and can be controlled by tuning both the pore size and the prevalence of pores .…”

Two-step spray-drying synthesis of dense and highly luminescent YAG:Ce3+ phosphor powders with spherical shape

“…To investigate the variations in porosity, specic surface areas of the particles were measured using nitrogen adsorption isotherms (Fig. According to a previous study in which YAG:Ce 3+ was prepared by a solid-state method, the pure YAG phase can be formed at temperatures above 1400 C. 32 For the YAG:Ce 3+ powders that we prepared by two-step spray drying, the pure YAG phase was obtained at a lower temperature of 1200 C. The XRD results indicate that all components of Y, Al, and Ce were homogeneously mixed in the YAG:Ce 3+ precursor powder obtained aer the rst spray drying, which is in a good agreement with the elemental mapping results shown in Fig. The corresponding BET surface areas were 8.3, 3.6, and 2.3 m 2 g À1 for the particles that were calcined at 1200, 1300, and 1400 C, respectively.…”

“…88-2048), without any impurity phases such as YAlO 3 (YAP) and Y 4 Al 2 O 9 (YAM). According to a previous study in which YAG:Ce 3+ was prepared by a solid-state method, the pure YAG phase can be formed at temperatures above 1400 C. 32 For the YAG:Ce 3+ powders that we prepared by two-step spray drying, the pure YAG phase was obtained at a lower temperature of 1200 C. The XRD results indicate that all components of Y, Al, and Ce were homogeneously mixed in the YAG:Ce 3+ precursor powder obtained aer the rst spray drying, which is in a good agreement with the elemental mapping results shown in Fig. 1(d) and 2(e).…”