Journal
JOURNAL OF PHYSICAL CHEMISTRY C
Volume 114, Issue 14, Pages 6681-6689Publisher
AMER CHEMICAL SOC
DOI: 10.1021/jp909197t
Keywords
-
Funding
- Hone Kong-France Research [9050206]
- City University Strategic Research [7002292]
Ask authors/readers for more resources
Borate phosphors, with formulations Y0.95Eu0.05BO3 (YBEu), Y0.95Tb0.05BO3 (YBTb), Y0.57Gd0.38Eu0.05BO3 (Y6G4BEu), and Y0.57Gd0.38Tb0.05BO3 (Y6G4BTb) have been synthesized by spray pyrolysis at the maximum temperature of 700 degrees C, and then annealed at 1200 degrees C. The yttrium oxide-doped phosphor Y0.95Eu0.05O1.5 (YOEu) was obtained by the same experimental conditions The UV-VUV excitation spectra of the samples were recorded using synchrotron radiation The emission intensities of these phosphors have also been investigated as a function of plasma gas pressure in a dedicated experimental setup. The intensities in the emission spectra were integrated, to compare the relative efficiencies of the phosphors All phosphors were more efficient with increasing gas pressure in the plasma chamber The emission intensity of YOEu was similar to that of YBEu or Y6G4BEu at low Ne-Xe pressure, but stronger at high pressure For both lanthanide activators. the mixed borates Y6G4B and the pure YBO3 (YB) have about same luminescence efficiency at low pressure, but the Y6G4B are better matt ices than YB at high Ne-Xe pressure With the introduction of Gd3+ in the borates. the emission intensity is enhanced due to a better spectral overlap with the plasma emission at 173 nun, and also the occurrence of multiple energy transfers between Gd3+ ions before transfer to the emitter Eu3+ or Tb3+ A color effect with the variation of pressure in the plasma chamber is observed for the Eu3+-doped phosphors The orange red intensity ratio (ie., D-5(0) -> F-7(0.1) (560-600 nm)/D-5(0) -> F-7(2) (600-640 nm)) increases as die gas pressure is raised. This observation is related to the spectral changes occurring in the plasma, and it is corroborated by the observation of selective excitation in the VUV range of Eu3+ at C-t versus C-1 crystallographic sites
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available