| White light-emitting diode (WLED) with lots of excellent properties, such as efficient, energy saving, environmental protection and long lasting lifetime, is a new solid state lighting technology. It is well known as the fourth-generation lighting source and deemed to a green light source for the 21st century. There are two kinds of approaches to achieve white-emitting LEDs, and the current mainstream of the fabrication of WLED is to combine yellow emitting lanthanide luminescence material with blue emitting LED. The progress of phosphor technology plays an essential role in the development of WLED.Currently, the WLED prepared using YAG:Ce phosphor has a shorter emission wavelength and a poor color rendering index (＜80), which leads to the output light partial to blue light, hence it will irritate people's eyes. In order to overcome the problem, we have prepared a kind of orange-yellow emitting phosphors which can be effectively excited by blue LED (the optimum emission is about 465 nm).Firstly, Eu2+ and Eu3+ co-doped aluminates luminescence nanomaterials MAl2O4:Eu2+, Eu3+ (M=Mg, Ca, Sr, Ba) have been prepared by sol-gel combustion method. We studied the structure, morphology and the luminescence properties of the samples. It shows that we can obtain pure crystalline products at 600℃. There exists emission of both Eu2+ and Eu3+ at the same time in the samples. The luminescence of MgAl2O4:Eu2+, Eu3+, CaAl2O4:Eu2+, Eu3+, BaAl2O4:Eu2+, Eu3+ are both at orange-yellow region, judged by their chromaticity coordinates.Secondly, we have synthesized MgxM1-xAl2O4:Eu2+, Eu3+(M=Sr, Ca, Ba) phosphors in order to enhance the emission of Eu3+ in MAl2O4:Eu2+, Eu3+. We have also investigated the influence of the ratio of two different alkali-earth ions, the combustion temperature, time, and the doping contents of Eu3+ on luminescent property. Mixed with a small amount of Mg ions, the samples maintained their own phase (MAl2O4 (M=Sr, Ca, Ba)). But when kept on increasing the contents of Mg ions, the products became to be the mixture of MAl2O4 and MgAl2O4, and finally, they turned to be MgAl2O4. Photoluminescence spectra indicated that the samples have the strongest emission when the combustion temperature was 600℃and the combustion time has nearly no effect on the luminescence intensities. When the doping content of Sr, Ca, Ba in MgAl2O4 was 10%, the luminous intensity of Eu3+ was significantly enhanced. And at the same time, the luminescence of Eu2+ was nearly the same as the products synthsised before. Moreover, the peak position of both Eu2+ and Eu3+ did not change. The luminescence of Mg0.9Sr0.1Al2O4:Eu2+, Eu3+ are still at orange-yellow region, but that of Mg0.9Ca0.1Al2O4:Eu2+, Eu3+ and Mg0.9Ba0.1Al2O4:Eu2+, Eu3+ have transferred to the red light area.Thirdly, aluminates luminescence nanomaterials co-doped by rare earth elements, such as Mg0.9Sr0.1Al2O4:Eu2+, Eu3+, Ce3+, Mg0.9Sr0.1Al2O4:Eu2+, Eu3+, Dy3+, and Mg0.9Sr0.1Al2O4:Eu2+, Eu3+, Pr3+ were prepared. We have also studied the crystal structure and luminescence properties. The doping of rare earth elements didn't change the structure of the sample. We have not found the luminescence of Ce3+,Dy3+,Pr3+ because of the trap level in the matrix and energy transfer between rare earth elements. The luminous intensity of Eu2+ was nearly the same as the products synthesised without co-doped rare earth elements. In the meanwhile, the emission intensity of Eu3+ was significantly reduced. However, the potion of emission peaks of both Eu2+ and Eu3+ did not change. Therefore, the output of the red light became decreased.
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