白光LED用红色荧光粉CeO_2∶Eu^(3+)的光谱性能研究

Spectroscopic Properties of CeO_2∶Eu^(3+) for White LEDs

使用共沉淀法制备不同掺杂浓度的CeO2∶Eu3+的荧光粉,并利用XRD,激发和发射光谱对其光学性质进行了研究。PL激发光谱中出现300~400nm的源于基质CeO2的强吸收宽带以及较弱的Eu3+的7 F0-5 D2(467nm)吸收峰。由于Ce4+和Eu3+半径十分接近,因而Eu3+在CeO2中具有较高的固溶度。当高浓度Eu3+掺杂CeO2时,出现了7F0-5 D2(467nm)吸收峰的极大增强。在467nm激发下获得了Eu3+的5 D0—7 F1(592nm)和5 D0—7 F2(612nm)跃迁的特征红光发射。与电荷迁移带激发下获得的红光相比,在467nm蓝光激发下获得的红光强度是其5倍。7 F0—5 D2(467nm)的强电子吸收与蓝光LED芯片的输出波长相匹配,在蓝光激发下获得明亮的红光发射。因此,Eu3+掺杂CeO2荧光粉是一种有潜力的用于白光LED的红色荧光粉。

Under different Eu3＋concentration,Eu3＋doped CeO2 was prepared by co-precipitation method,and the structure and luminescent properties were studied through XRD,excitation and emission spectra.The PLE spectrum shows a broad chargetransfer band from 300~400nm,and a week excitation line at 467 arise from7 F0—5 D2 transition in Eu3＋.The red emission arise from5 D0—7 F1（592nm）and 5 D0—7 F2 transitions of Eu3＋has a great increase by high concentration doping under 467 nm excitation.The wavelength at 467 nm is nicely fitting in with the widely applied emission wavelengths of blue LED chips.It is indicated that the CeO2∶Eu3＋phosphor emits efficiently red emission under the blue light which makes it possible to create white light from a combination of a blue LED chip.