Synthesis and luminescence properties of Y2.94Al5−mGamO12:0.06Ce3+ (1≤m≤2.5) green phosphors for white LEDs

Abstract

A series of Y2.94Al5−mGamO12:0.06Ce3+ (1≤m≤2.5) green phosphors were successfully synthesized by a solid-state reaction method. The microstructure, morphology, luminescence spectra and thermal stability of the phosphors were investigated. NaF flux can greatly promote the growth and crystallization of Y2.94Al5−mGamO12:0.06Ce3+ (1≤m≤2.5) phosphors. The luminescence properties of Y2.94Al5−mGamO12:0.06Ce3+ (1≤m≤2.5) green phosphors dramatically depend on the m value. When m≤1.5, the phosphor shows strong luminescence and excellent thermal stability. At 150°C, the luminescence intensity of the m=1.0 and m=1.5 samples still maintains 90.3% and 88.8% of that measured at 25°C, respectively. The experimental results demonstrate that Y2.94Al4GaO12:0.06Ce3+ and Y2.94Al3.5Ga1.5O12:0.06Ce3+ are promising green phosphors, which have great potential for use not only in high color rendering index white LEDs but also in high-power white LEDs.