Optical and reliability properties studies of green YAG phosphors by Ga substitution.

In this paper, green Y(AlGa)O:0.06Ce phosphors were prepared by conventional solid-state reaction. The crystal structures, the influence of Ga concentration on the photoluminescence, thermal stability and reliability properties of the phosphors were studied. The PL emission bands of Y(AlGa)O:0.06Ce showed blue shift from 545 nm to 525 nm with increasing Ga content (x value) under excited at 460 nm. The thermal stability of Y(AlGa)O:0.06Ce phosphor is hindered by adding Ga. As the temperature increases from 300 to 500 K, the PL intensity of Y(AlGa)O:0.06Ce and Y(AlGa)O: 0.06Ce phosphor decreases by 11.11 and 16.57 %, respectively. Reliability test results show that the relative PL intensity of Y(AlGa)O:0.06Ce phosphor decrease to from 99.76 to 95.37 % with x value increased from 0.15 to 0.35 after the ambient condition of 85 °C/RH 85 % for the exposure time of 168 h. And the relative PL intensity of Y(AlGa)O:0.06Ce phosphor decrease to from 99.53 to 91.78 % after soaking into boiled water for 4 h. It can be summarized that the addition of Ga deteriorates the thermal stability as well as the reliability of the phosphors slightly. [ABSTRACT FROM AUTHOR]