Synthesis and Luminescent Properties of a Novel Red-Emitting Phosphor Ba_2ZnSi_2O_7:Eu~3+, B~3+ for Ultraviolet Light-Emitting Diodes

摘要

A novel red-emitting phosphor Ba_1.95ZnSi_2O_7:Eu_0.05~3+, B_x~3+ was prepared by combustion synthesis and an efficient red emission under near-ultraviolet (UV) was observed. The luminescence, crystallinity, and particle sizes were investigated using luminescence spectrometry, X-ray diffractometry, and scanning electron microscopy. The emission spectrum shows that the most intense peak is located at 614 nm, which corresponds to the ~5D_0_~7F_2 transition of Eu~3+.The phosphor has two main excitation peaks located at 394 and 465 nm, which match the emission of UV and blue light-emitting diodes, respectively. The optical absorption spectra of Ba_1.95 ZnSi~2O_7:Eu_0.05~3+ B~0.06~3+ exhibited a band-gap energy of 3.95 eV. The results showed that boric acid was effective in improving the luminescence intensity of 1.95 ZnSi~2O_7:Eu_0.05~3+, and the optimum molar ratio of boric acid to zinc nitrate was about 0.06. The phosphor 1.95 ZnSi~2O_7:Eu_0.05~3+ B~0.06~3+ synthesized by the combustion method showed 1.8 times improved emission intensity compared with that of the 1.95 ZnSi~2O_7:Eu_0.05~3+ B phosphor under λ_cx=394 nm.