Photoluminescence properties of Eu3+ and Bi3+ in YBO3 host under vacuum ultraviolet/ultraviolet excitation

The photoluminescence properties of Bi3+/Eu3+ doped YBO3 phosphors under 147, 168, 185, 222, and 262 nm excitation were studied in this paper. The sensitization luminescence of Eu3+ by Bi3+ was demonstrated and a useful concentration scope, which is 0.05-0.25 mol %, for Bi3+ doped into YBO3: Eu3+ as candidate of plasma display panel red phosphor was optimized. The relative emission intensity of Bi3+ ions occupying C-3 sites in YBO3 crystal increases gradually with Bi3+ concentration increasing, while the emission of Bi3+ occupying S-6 sites decreases because of energy transfer from S-6 sites to C-3 sites. The peak of emission band changes from 295 to 320 nm as Bi3+ concentration increases from 0.1 to 0.25 mol %. Therefore, 0.25 mol % is the critical concentration for Bi3+ ions to transfer their absorption energy between different sites at room temperature. As a result, the luminescence of YBO3: Bi3+, Eu3+ decreases as Bi3+ concentration increases further. (C) 2009 American Institute of Physics. [DOI: 10.1063/1.3053689]