Sol-Gel Auto-Combustion Synthesis and Luminescence Properties of GdCaAl3O7:RE3+(RE=Eu, Tb, Eu@Tb) Phosphors For Near-Ultraviolet Light-Triggered Indoor Illumination

Abstract

The color-tunable GdCaAl3O7: RE3+ (RE=Eu, Tb, Eu@Tb) phosphors were synthesized via an ultrafast sol-gel auto-combustion synthesis method. The XRD (X-ray diffraction) patterns confirmed the forming of GdCaAl3O7 tetragonal phase, and the SEM (Scanning electron microscopy) images indicated that the obtained products presented honeycomb-like structure due to the gas releasing during the auto-combustion process. The EDS (Energy dispersion spectra) results suggest that Eu3+ and Tb3+ were well incorporated into the host matrices of GdCaAl3O7. The luminescent properties, concentration quenching mechanism, energy transfer mechanism, luminescent dynamics, thermal stability and product practicability of GdCaAl3O7: R3+ (RE=Eu, Tb, Eu@Tb) phosphors were investigated systematically. All the GdCaAl3O7: RE3+ (RE=Eu, Tb, Eu@Tb) products presented the characteristic emission of doped RE3+. Using GdCaAl3O7: 50% Tb3+@3.0% Eu3+ as yellow-emitting phosphors in combination with commercial BAM: Eu2+ 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.