In the present study, we fabricated the red phosphor $SrTiO_3$:Pr,Al by solid state reaction and analysed phosphor characteristics using X-ray diffractormeter, cathodoluminescence spectrometer and transmission electron microscopy. The relationship between luminescent properties and microstructures of $SrTiO_3$:Pr,Al phosphor was studied. The formation of the second phases in $SrTiO_3$:Pr,Al phosphor and the microstructure of electrophoretically deposited phosphor thin films were studied by transmission electron microscopy.
The synthesized $SrTiO_3$:Pr,Al phosphor showed the characteristic x-ray diffraction patterns of the perovskite structure and the average particle size of 0.5 ~2 ㎛ for particle size distribution analysis. The synthesized $SrTiO_3$:Pr,Al phosphor showed the red emission which is narrow. The maximum emission peak appeared at 615nm wavelength because of the transition from $^1D_2$ to $^3H_4$ in $Pr^{3+}$ ion. The luminescence efficiency of $Pr^{3+}$ is increased by Al addition. There was no peak shift as the Al coactivator added. According to the result of EDS spectra and TEM analysis, a small part of added Al ions were incorporated into the lattice and the rest was consumed in the second phases. The second phases which exist in $SrTiO_3$:Pr(0.2 m/o),Al(23.0 m/o) phosphor are monoclinic $SrAl_2O_4$, hexagonal $TiO_2$, triclinic $Ti_4O_7$, hexagonal $SrAl_{12}O_{19}$.
The microstructure of electrophoretically deposited phosphor thin films showed that phosphor particles were closely packed and that all the space among phosphor particles from the substrate to 3 phosphor layers was filled with the binder material. At as-deposition state the binder material is an amorphous $Mg(OH)_2$ and after heat treatment MgO which is partially amorphous and partially crystalline.
