The invention relates to secondary excitation type orange-red fluorescent
powder and a preparation method thereof, belonging to the technical field of luminescent materials. The fluorescent
powder is Sr1-a-bCa1-x-cAl2-yMexREyO4S:aEu<2+>,bDy<3+> and cTm<3+>, where Me is at least one of Zn, Cd, Mg, RE is at least one of Ga, Zn, Ge, and Si, 0<x<0.1,0<y<0.2, 0<a<0.12, 0<b<0.1, and 0<c<0.1. The design idea is that: Eu<2+> and Tm<3+> are taken as a luminescent center and Dy<3+> and the like are added to be taken as an auxiliary excitant; the light of the Eu<2+> and Tm<3+> interacts; incident light from outside excitates Eu<2+> to emit light which excitates Tm<3+> to emit light again to form a secondary excitation type
light emission; the relative ratio of Eu<2+> to Tm<3+> determines the color of the emitted light; and the concentration of Dy<3+> determines the
afterglow time of the secondary excitation long-
afterglow fluorescent
powder. The preparation method comprises the following steps: weighing each
oxide raw material according to the ratio of each element in the
structural formula, adding a fluxing agent into the raw materials and uniformly mixing the mixture by ball milling, placing the obtained product in a
reducing atmosphere for calcinations, and crushing and screening the obtained product to obtain the required fluorescent powder. The secondary excitation type orange-red fluorescent powder can emit orange-red
fluorescent light, and the
afterglow time can reach 8 to 12 h.