Effects of doping Pr3+and Gd3+into YAG: Ce phosphors on the luminescence properties

A series of ( Y0.98- x- yCe0.02PrxGdy) 3Al5O12 ( x = 0- 0.02, y = 0, 0.3) phosphors were prepared by a modified co- precipitation method. The phases, luminescence properties, effect of calcination temperature on luminescence properties and energy transfer ( ET) were investigated. The results indicated that the doping of Pr3+ andGd3+ in all samples did not produce any new phases but caused a slight lattice expansion. The series of ( Y0.98- xCe0.02Prx) 3Al5O12 phosphors emit additional red light at 612 nm, and when x = 0.005, the red/ yellow ratio of the emission spectrum is the largest. Compared with the ( Y0.975Ce0.02Pr0.005) 3Al5O12 phosphor, continued doping 30 at% Gd3+ in the ( Y0.675Ce0.02Pr0.005Gd0.3) 3Al5O12 sample makes the peak wavelength of yellow light emission shift from 533 to 561 nm. Doping Pr3+ and Gd3+ results in the decrease of integrated emission intensity, but the emission intensity and the red/ yellow ratio can be increased by raising the calcination temperature. In addition, there is only the ET from Ce3+ to Pr3+ in the ( Y0.675Ce0.02Pr0.005Gd0.3) 3Al5O12 sample.