Synthesis of High-Brightness Blue-Emitting Phosphors Sr2MgSi2O7:Eu~(2+), Er~(3+) by Gel-Combustion Method Assisted by Microwave and their Properties

摘要

High-brightness blue emitting phosphors Sr2MgSi2O7:Eu~(2+), Er~(3+) were synthesized successfully by gel-combustion method assisted by microwave. The as-synthesized phosphors were analyzed and characterized by X-ray diffraction and fluorescence spectrophotometer. The influences of co-doped Er~(3+) concentration, fuel urea and flux H3BO3 on luminescent properties of samples were investigated. The results show that Sr2MgSi2O7: Eu~(2+), Er~(3+) phosphors possess the tetragonal crystal structure similar to that of Sr2MgSi2O7. The excitation spectrum shows a broad band from 250 to 450 nm and the strongest excitation peak is at 358 nm. The emission spectrum excited by 358 nm also shows a wide band with the main peak at ca, 467 nm, which is ascribed to the typical transition from 4f~65d~1 to 4f~3 of Eu~(2+). It is found that co-doped Er~(3+) can sensitize effectively the luminescence of Eu~(2+) ions in Sr2MgSi2O7 host. The luminescence intensity reaches the strongest when the concentration of co-doped Er~(3+) is 0.01, the mass ratio of urea to nitrate is 1.5:1 and the mole fraction of H3BO3 is 15 % and it is about 1.3 times of single-doped Eu~(2+) sample.