부산대학교 도서관

Rare earth-free phosphor materials have been synthesized via aliovalent doping of [PO4]3−and [HfO4]4−for [AlO4]5−and [GaO4]5−in the Sr3MO4F host lattice (space group I4/mcm). High temperature synthesis was used to synthesize the novel products Sr2.5-xBa0.5Al1-xPxO4F (0.05 ≤ x≤ 0.15), Sr2.5-xBa0.5Ga1-xPxO4F (0.05 ≤ x≤ 0.15) and Sr2.5−x2Ba0.5Al1−xHfxO4F(0.025 ≤ x ≤0.075). The structures of these oxyfluorides were analyzed via powder X-ray diffraction (PXRD) and neutron powder diffraction (NPD), and their photoluminescent properties were analyzed through spectrofluorimetry before and after being treated under reducing conditions. Optimal doping was found at a concentration of x= 0.10 for Sr2.5-xBa0.5Al1-xPxO4F (a= 6.8762(4) Å; c= 11.1273(6) Å) resulting in a maximum emission at 454 nm when excited at 214 nm and x= 0.05 for the Ga analog (a= 6.87591(7) Å; c= 11.3722(2) Å) corresponding to an emission centered around 529 nm from excitation with 227 nm. When doping with Hf4+the optimal concentration for Sr2.5−x2Ba0.5Al1−xHfxO4Fwas x= 0.025 (a= 6.8607(1) Å; c= 11.1682(3) Å), resulting in a broad emission between 410–600 nm when excited at 251 nm.