Vapor phase synthesis of nanocrystalline YAG:Ce

Heiko Paul 1Harald Kaps 1Ulrich Herr 1Martin Zachau 2

1. Ulm University, Albert-Einstein-Allee 47, Ulm 89081, Germany
2. OSRAM GmbH (OSRAM), Munich, Germany

Abstract

Nanocrystalline YAG:Ce (Y3Al5O12:Ce) is a highly efficient phosphor used for light conversion in white LEDs. YAG:Ce with an average particle size of 10…50 nm is a promising candidate for this application. We report about synthesis of YAG by vapor phase reaction (CVR) in a hot-wall reactor. In a first step the formation of the YAG phase by CVR has been studied. Structural analysis of the phases formed using different synthesis parameters was done by x-ray diffraction. It is found that up to a temperature of 1200 °C other Y-Al-oxides form instead of YAG. Scanning calorimetry experiments (DSC) have been performed in order to investigate the phase formation at different temperatures and heating rates. These results serve as a basis for the modeling and the optimization of the parameters of the CVR synthesis. Samples with Ce concentrations ranging from 0,1 at.% to 4,2 at.% have been prepared to investigate the influence of the doping concentration on the luminescence of the YAG:Ce. Photoluminescence has been used to investigate the optical properties of the YAG host lattice doped with Cerium. We will report on the results of as-prepared and annealed samples.

 

Related papers
  1. Optical properties of nanocrystalline YAG:Ce
  2. Concentration dependent fluorescence lifetime in nanocrystalline Y2O3:Eu phosphors
  3. Nanomaterials for lighting
  4. Physics of Nanocrystalline Luminescent Ceramics

Presentation: Poster at E-MRS Fall Meeting 2006, Symposium C, by Heiko Paul
See On-line Journal of E-MRS Fall Meeting 2006

Submitted: 2006-05-12 06:52
Revised:   2009-06-07 00:44