The Emission Property of Al-doped SiO₂: Eu Phosphor and Local Structure Around Eu by an EXAFS Study

Abstract

Al-doped SiO₂: Eu phosphors were prepared by alkoxide method. The emission of the phosphor showed a red color with a main peak at 610 nm, and changed into a blue color of 470 nm by a reduction with hydrogen. This suggests that the europium ions were converted from trivalent to divalent by changing the firing conditions. On the other hand, the phosphors without an Al dopant did not emit light after reduction. Structural information on the difference in the emission property was obtained by EXAFS. It was found that the Eu ions in the Al doped SiO₂: Eu were linked to the Al atoms through the Eu-O-Al bonds. The role of the Al dopant was discussed on the basis of the change in the local structure around Eu ions.