两步反应法制备硅基氮氧化物荧光材料SrSi_2O_2N_2:Eu~(2+)及其发光性能研究

本文以硅酸盐相Sr2SiO4:Eu2+为前驱体,采用两步反应法制备了一系列单相的氮氧化物荧光粉Sr1?xSi2O2N2:Eu2+x(0.02?x?0.10),详细探讨了SrSi2O2N2:Eu2+荧光粉的反应机制及发光性能.实验结果显示所有样品能被近紫外光(400 nm)和蓝光(450 nm)激发发射出峰值位于535 nm的黄绿光,在Sr2SiO4:Eu2+体系中Eu2+的最佳掺杂浓度值x为0.05,Eu2+之间的能量传递是电偶极-偶极相互作用,Eu2+之间能量传递临界距离Rc=1.507 nm.此外,本文还对样品的发光强度和热稳定性与某商用YAG黄粉作了分析比较,所有结果表明该系列荧光粉可用于白光LED制造.

Structure and photoluminescence properties of SrSi2O2N2：Eu^2＋ phosphors prepared by two-step solid state reaction using SrSi2O2N2：Eu^2＋ as a precursor

A series of yellow green emitting phosphors nitrogen oxides Sr1-xSrSi2O2N2：Eu^2＋x（0.02≤x≤0.10） were synthesized by a method using SrSi2O2N2：Eu^2＋ as a precursor and their photoluminescence properties and reaction mechanism were investigated in detail. The photoluminescence results show that all samples can be excited efficiently by UV （400 nm） light and blue （450 nm） light and emit yellow green （535 nm） light with line spectra, which are coupled well with the characteristic emission from UV-LED and blue LED, respectively. The experimental results and their analysis suggest that the optimum concentration of Eu^2＋ is 0.05 mol and the energy transfer occurs due to dipole-dipole interactions among Eu^2＋ ions in Sr1-xSrSi2O2N2：Eu^2＋x, the critical distance （Re） of energy transfer was calculated to be about 1.507 nm. Furthermore, the thermal stability and the emission intensity of synthesized SrSi2O2N2：Eu^2＋x phosphor was examined and compared with that of commercial YAG yellow phosphors. All the results indicate that the phosphor is a suitable candidate of yellow green emitting phosphor for the fabrication of white LEDs.