High efficient blue emission of Ce3+ activated Ca4P2O9 phosphor for white LEDs

Intense blue emission from Ca(4)P(2)O(9):Ce(3+) phosphor was observed with CIE chromaticity coordinates (0.157, 0.094) and a high external quantum yield up to 64.8%. Concentration quenching effect of Ca(4)P(2)O(9):xCe(3+) indicated that the optimal Ce(3+) concentration was at x = 0.005, and the energy transfer among the nearest neighbor ions accounted for this quenching. Good thermal stability of the optimal phosphor was also shown, since 90% of the initial intensity (at 300 K) remained as the temperature increased from 300 to 400 K. Ca(4)P(2)O(9):0.005Ce(3+) can act as a promising blue-emitting phosphor for white LEDs.