1. Key Laboratory of Interface Science and Engineering in Advanced Materials of Taiyuan University of Technology, Ministry of Education, College of Materials Science and Engineering of Taiyuan University of Technology, Taiyuan 030024, China 2. College of Chemistry and Engineering of Taiyuan University of Technology, Taiyuan 030024, China
Abstract：Using rare earth oxides as raw materials, yttrium aluminum garnets activated by cerium and gadolinium ions were prepared by high energy ball milling and solid-state reaction at 1 300 ℃. The crystal structures of the products were studied by XRD, and the luminescence characteristics of Ce ion and the influence of Gd ion were studied by emission and excitation spectra. The results indicated that the products were yttrium aluminum garnet crystals of cubic system, and they were excited by blue light chips effectively. The emission peak of phosphors could change among 530-560 nm by adjusting the mole density of doping ions. The red shift of emission spectra could be interpreted with the configuration coordination figure. White LEDs were fabricated by phosphor conversion. When electric current is 20 mA, and the working voltage is 3.5 V, the white light LED chromaticity coordinates are x=0.310 and y=0.323, the lumen efficiency is 26.131 m·W-1,the color rendering index is 81.8, and the color temperature is 6 605 K.
