Phase composition and luminescent properties of strontium aluminate long persistence phosphor synthesized by combustion synthesis method with different Sr/Al ratios

摘要

Strontium aluminate long persistence phosphors are synthesized by combustion method. By controlling the raw material ratio(Sr/Al), the effects of phase composition on subsequent spectroscopic properties of phosphors are studied. Results show that the phase composition changes from strontium-rich phase to aluminumrich phase with the decrease of Sr/Al: when the rate of Al/Sr changes from 3:1 to 1:1, the main crystal phase of samples is Sr3Al2O6, and it exhibits the characteristic fluorescence of Eu 3+ in the lattice of Sr3Al2O6; when the rate of Al/Sr is between 1:2 and 2:7, phase composition is the mixture of SrAl2O4 and SrAl4O7, and it emits the characteristic fluorescence of Eu2+ in SrAl2O4 but not in SrAl4O7; when Al/Sr decreases to 1:4 or even 1:12, the main crystal phase of samples transform into SrAl12O19, and the characteristic emission peak is about 470 nm, which corresponds to the characteristic emission of Eu2+ in SrAl12O19. At the end of the article, the influence laws of two different synthesis methods on phase composition of samples between high-temperature solid method and combustion method are compared. Compared with the high-temperature solid method, the rule of influence is similar, but the mole ratio of Al/Sr in products is always higher than the initial ratio of the raw material, and compounds like Sr4Al14O25 are not obtained by combustion method.