Reduction of the Deterioration of Luminescence Efficiency of P-53 Phosphor Due to Electron Bombardment

In order to withstand high excitation power density for the long operational lifetime required, preparation processes have been improved to reduce the deterioration of the luminescence efficiency of P-53 phosphors due to electron bombardment. The effects of several factors on the luminescence efficiency and the resistivity to high electron bombardment were evaluated. P-53 phosphors should be single-phase cubic YAG and have good surface crystallinity. In order to compensate for the change in charge by Ba2+(flux) taken up inside the phosphor particles, addition of tetravalent metal compounds to the starting materials was performed and the addition of SiO2 was found to be effective. As a result, the deterioration of brightness due to electron bombardment could be reduced by about 70%, while high luminescence efficiency was maintained.