Control of spectral properties of strontium-alkaline earth-silicate-europium phosphors for LED applications

Abstract

SiO4-based phosphors doped by Eu2+ were studied for use in white light emitting diodes (LEDs). Variations of excitation and emission spectra by changes in the alkaline earth ions in host lattice were studied. It was found that the Sr2SiO4:Eu-Ba2SiO4:Eu system was excellent for white LED applications with excitation in the 380-465 nm region. Specially, the yellow light intensity from (Sr,Ba)SiO4:Eu was comparable to yttrium aluminum garnet:Ce phosphors for excitation at 465 nm (blue-emitting LED). The peak excitation wavelength could be controlled by the Ba/Sr ratio in the host lattice. Also, it was found that (Sr,Mg)SiO4:Eu phosphors efficiently emit blue light at 405 nm excitation. (c) 2005 The Electrochemical Society.