Temperature-dependent photoluminescence properties of (Y, Lu) 3Al5O12:Ce3+ phosphors for white LEDs applications

摘要

The effects of the excitation wavelength, Ce3+ concentration and chemical substitution on the thermal quenching of Y3Al 5O12:Ce3+ (YAG:Ce3+) phosphors were investigated over a temperature range from 30 to 250 °C. The quenching behavior exhibits a complex dependence on the excitation wavelength and Ce 3+ concentration, which can be attributed to temperature-dependent absorption strength of the different fd absorption bands and thermally activated concentration quenching with or without energy migrations between Ce 3+ ions, respectively. With increasing Lu3+content the luminescence of (Y, Lu)3Al5O12:Ce3+ phosphors shows a pronounced blueshift, and simultaneously the temperature quenching is obviously improved due to a decrease in Stokes shift.