Luminescent properties of trivalent praseodymium-doped barium zinc sulfide

Ba2ZnS3: Pr phosphors, emitting white to green light, were synthesized by the double-crucible method. X-ray diffraction results indicate that the raw materials were completely sulfurized at 1000 degrees C for 2 h. All samples doped with 0.05 - 10 mol % Pr3+ had orthorhombic crystal structures. The emission spectra are the results of (i) host-activator transition and (ii) direct excitation of Pr3+ ions. Obtained using 365-nm UV light, the photoluminescence spectra include emission peaks between 470 and 520, 530 and 570, and 585 and 665 nm. The maximum emission peak at 493 nm is associated with the P-3(0) --> H-3(4) transition, and the intensity was maximal at a doping concentration of 0.2 mol %. The D-1(2) - H-3(4) transitions, like the CIE (Commission Internationale de l'Eclairage) color coordinate from the white region to the green region, are sensitive to the concentration of the dopant Pr3+ ions. In response to excitement using 456-nm purplish blue light, the maximum emission intensity at 493 nm was maximal at a doping concentration of 2 mol %. The D-1(2) - H-3(4) emission peaks almost disappeared, and the CIE color coordinates are all in the green region. (C) 2006 The Electrochemical Society.