Sol-gel auto-combustion synthesis and luminescence properties of GdCaAl3O7: RE3+ (RE=Eu, Tb, Eu@Tb) phosphors for near-ultraviolet light-triggered indoor illumination

The color-tunable GdCaAl 3 O 7 : RE 3+ (RE = Eu, Tb, Eu@Tb) phosphors were synthesized via an ultrafast sol-gel auto-combustion synthesis method. The X-ray diffraction patterns confirmed the forming of GdCaAl 3 O 7 tetragonal phase, and the scanning electron microscopy images indicated that the obtained products presented honeycomb-like structure due to the gas releasing during the auto-combustion process. The luminescent properties, concentration quenching mechanism, energy transfer mechanism, luminescent dynamics, thermal stability and product practicability of GdCaAl 3 O 7 : RE 3+ (RE = Tb, Eu, Eu@Tb) phosphors were investigated systematically. All the GdCaAl 3 O 7 : RE 3+ products presented the characteristic emission of doped RE 3+ . Using GdCaAl 3 O 7 : 50% Tb 3+ @3.0% Eu 3+ as yellow-emitting phosphors in combination with commercial BAM: Eu 2+ blue-emitting phosphors and a NUV chip can successfully package a warm white LED device with high color rendering index (CRI, 86.3) and low correlated color temperature (CCT, 3348 K) that was very suitable for near-ultraviolet light-triggered indoor illumination.