白光LED用新型红色荧光粉SrMgSi2O6:Eu3+, M(M=Gd3+, Ti4+)的合成及性质

Preparation of New Red Emitting Phosphor SrMgSi2O6:Eu3+,M (M=Gd3+, Ti4+) for White LEDs and Its Properties

摘要:

以Na2CO3为电荷补偿剂，采用凝胶-燃烧法合成新型红色硅酸盐发光材料SrMgSi2O6:Eu3+。用X射线粉末衍射仪、荧光分光光度计等对合成产物进行分析和表征。结果表明：SrMgSi2O6:Eu3+ 的晶体结构与Sr2MgSi2O7相同，同属四方晶系。样品SrMgSi2O6:Eu3+的激发光谱在220～300 nm出现一宽带吸收，归属于O2--Eu3+之间的电荷迁移，300 nm以后出现的锐线峰为Eu3+的f-f跃迁吸收峰，其最强锐线峰位于400 nm，因而，可以被InGaN管芯产生的紫外辐射有效激发。发射光谱由两个强发射峰组成，位于592和618 nm处，分别属于典型的Eu3+的5D0→7F1和5D0→7F2跃迁。此外，研究发现：共掺Gd3+或Ti4+均能敏化Eu3+的发光，可有效提高样品的红光发射。因此，SrMgSi2O6:Eu3+, M(M=Gd3+, Ti4+)有望成为一种与InGaN管芯匹配的白光LED用红色荧光粉

Abstract:

Novel red phosphors SrMgSi2O6:Eu3+ were synthesized by a gel-combustion method, with Na2CO3 as the charge compensation agent. The as-synthesized phosphors were analyzed and characterized by XRD and fluorescence spectrophotometer. The results show that the SrMgSi2O6:Eu3+ phosphor possesses a tetragonal crystal structure which is similar to that of Sr2MgSi2O7. The excitation spectrum of the SrMgSi2O6:Eu3+ sample presents wide band absorption between 220 and 300 nm, which is ascribed to the charge transfer between Eu3+ and O2-. The sharp peaks appearing after 300 nm belong to f-f transition of Eu3+, and the strongest sharp peak is located at 400 nm. Therefore, samples can be efficiently excited by ultraviolet radiation from InGaN chip. The emission spectrum consists of two strong emission peaks at 592 nm and 618 nm, which are ascribed to 5D0→7F1 and 5D0→7F2 respectively. Moreover, it is found that co-doped Gd3+ or Ti4+ can sensitize the luminescence of Eu3+ in SrMgSi2O6:Eu3+, in other words, co-doped Gd3+ or Ti4+ can improve red light emission of samples efficiently. So SrMgSi2O6:Eu3+, M(M=Gd3+, Ti4+) shows good prospect for red phosphors of white LED