Tunable Luminescence and Energy Transfer in Novel Blue-Green-Emitting BaGd2Si3O10:Ce3+, Tb3+ Phosphors for Near-UV-Based White LEDs

A new series of Ce3+ singly doped and Ce3+/Tb3+-co-doped BaGd2Si3O10 (BGSO) phosphors have been synthesized by a high-temperature solid-state reaction technique. The phase purity, luminescence properties, energy transfer mechanism, internal quantum efficiency, and thermal stability of as-prepared phosphors were investigated in detail. The photoluminescence spectra of BGSO:xCe(3+) phosphors exhibited broad emission in the wavelength range of 350-600 nm with a peak maximum at 427 nm. Under 336 nm excitation, the tunable blue-green luminescence of BGSO:0.04Ce(3+), yTb(3+) phosphors was investigated as a function of Tb3+ concentration and well demonstrated by the energy transfer mechanism from Ce3+ to Tb3+ ions. The critical distance (R-c) of energy transfer was estimated using concentration quenching method, and its value was found to be 10.75 angstrom. The thermal stability and activation energy of thermal quenching were analyzed for composition-optimized BGSO:0.04-Ce3+, 0.30Tb(3+) phosphors by varying the temperature from 303 to 483 K. The results obtained from the present investigation suggested that Ce3+ - and Ce3+/Tb3+-activated BGSO phosphors can serve as promising materials for near-UV-based phosphor-converted white light-emitting diodes.