Developments of crystal structures and photoluminescence properties of Sr0.85Eu0.15Al12O19 green phosphors using different synthesis parameters

Abstract

First, a solid-state reaction method was used to synthesize a Sr[Formula: see text]Eu[Formula: see text]Al[Formula: see text]O[Formula: see text] phosphor at 1250[Formula: see text]C–1400[Formula: see text]C for 1 h, and its crystal structures and photoluminescence properties were investigated as a function of synthesis temperature. When the furnace reached the synthesis temperature, the 5% H[Formula: see text] N2 reduction atmosphere was infused and the reduction atmosphere was removed as the temperature was dropped to 800[Formula: see text]C. When 1200[Formula: see text]C was used as the synthesis temperature, the SrAl[Formula: see text]O[Formula: see text], SrAl2O4, and SrAl4O7 phases co-existed; only one weak emission peak was observed in the photoluminescence excitation (PLE) spectra, and two weak emission peaks were observed in the photoluminescence emission (PL) spectra. When the Sr[Formula: see text]Eu[Formula: see text]Al[Formula: see text]O[Formula: see text] phosphors were synthesized at a temperature higher than 1200[Formula: see text]C, the diffraction intensities of SrAl[Formula: see text]O[Formula: see text], SrAl2O4, and SrAl4O7 phases were almost unchanged, but the crystal sizes of Sr[Formula: see text]Eu[Formula: see text]Al[Formula: see text]O[Formula: see text] powders increased. For Sr[Formula: see text]Eu[Formula: see text]Al[Formula: see text]O[Formula: see text] phosphors, PLE spectra had one broad exciting band with two centered wavelengths of 317 and 365 nm, and PL spectra had one emission band with one centered wavelength of 513 nm. As the synthesis temperature rose, the emission intensities of PLE and PL spectra increased. Second, we show that the removed temperature of reduction atmosphere of Sr[Formula: see text]Eu[Formula: see text]Al[Formula: see text]O[Formula: see text] phosphors had an apparent effect on their emission properties of PLE and PL spectra.