Potential white-light long-lasting phosphor: Dy3+-doped aluminate

The white-light long-lasting phosphor CaAl249/2O: Dy3+ was prepared and investigated. The white-light afterglow spectra under the irradiation of 254 or 365 nm are comprised of the blue light emission and the yellow light emission, originating from the transitions of 4F (6H)(, 4F)(15/2)(9/2) (6H)(13/2) (in the 4f)(9) configuration of Dy3+. The afterglow can last 32 min for the best sample with Dy-doped concentration of 2 at. %. The decay curve and the thermoluminescence curve show to be a second-order process. Thermoluminescence curves exhibit a complicated structure in the range of 230-450 K with the peaks at 244, 280, 310, and 346 K. The two thermoluminescence bands peaking above room temperature have corresponding traps with the depths of 0.54 and 0.61 eV, which are responsible for the afterglow emission at room temperature. This work provides a promising approach for the development of white-light long-lasting phosphor. 2005 American Institute of Physics.