Single phase Tb3+ activated Y3GaO6 nanophosphor: Synthesis, structural refinement and luminescence properties for display applications

Phosphor materials having composition Y 3-x GaO 6 :xTb 3+ (x = 1-7 mol %) were synthesized by a simple, rapid and cost-effective solution combustion approach. This study presents a systematic investigation of Tb 3+ doped Y 3 GaO 6 phosphors including the relation between structural characteristics, dopant concentration and photoluminescent behavior to optimize emission performance. The formation of a single-phase orthorhombic Y 3 GaO 6 structure having Cmc21 space group was confirmed via XRD (X-ray diffraction) analysis. FE-SEM (Field Emission Scanning Electron Microscopy) images confirmed the presence of nanoparticles with average particle size in the range of 35-55 nm. The presence of Y, Ga, O and Tb elements was confirmed by EDX (Energy Dispersive X-ray) spectroscopy. Under 267 nm excitation, a narrow and radiant green emission peak at 547 nm attributed to transition 5 D 4 → 7 F 5 was observed in PL (photoluminescence) spectra of Y 3 GaO 6 :Tb 3+ phosphors. The temperature dependent PL analysis confirmed good thermal stability of the synthesized phosphors retaining 84 % of the initial intensity at 473 K. The PL emission intensity increased on increasing Tb 3+ amount up to 4 mol % then decreased as a result of concentration quenching. The quenching observed at higher concentrations was explained by dipole-dipole interactions between Tb 3+ activator ions. The luminescence decay measurements were well fitted using bi-exponential function with an average lifetime of 2.33 ms of the optimized sample. The calculated CIE coordinates, CCT (Correlated Color Temperature) and color purity values revealed green emission characteristics. The results demonstrate that Y 3 GaO 6 :Tb 3+ phosphors are promising candidates for green emitters in display devices and solid-state lighting applications.