Enhancement of luminescent properties in Eu3+ doped BaNb2O6 nanophosphor synthesized by facile metal citrate gel method

Abstract Eu3+ doped BaNb2O6 nanophosphors were successfully synthesized using facile metal citrate gel (MCG) method. Thermo-gravimetric analysis (TGA) - differential scanning calorimetric (DSC), X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM) and photoluminescence spectra were employed to characterize the synthesized phosphors. TGA-DSC reveals that the sample initiate to crystallize at 900 °C, and the XRD confirms that the pure BaNb2O6 phase was obtained at 1000 °C. FE-SEM images indicate that the BaNb2O6: Eu3+ powder consist of fine and sphere-shaped grains with the size of around 60–70 nm. Under the excitation of n-UV (395 nm) and blue (466 nm), the BaNb2O6: Eu3+ phosphor exhibits the characteristic emission bands of Eu3+ corresponding to 5D0 →7FJ (J = 0, 1, 2, 3, 4) transitions. The emission spectrum exhibits three-fold enhancement in intensity relative to the bulk phosphor. The optimum concentration was observed as 12 mol% of Eu3+ ions in BaNb2O6 host. The Judd-Ofelt intensity parameters ΩJ (J = 2, 4) for Eu3+ doped BaNb2O6 nanophosphors were calculated. The evaluated chromaticity coordinates are very close to the commercial phosphor Y2O2S: Eu3+ and NTSC standard phosphors. The decay curve analysis has been measured for the synthesized phosphor. The experimental results suggest that Eu3+: BaNb2O6 phosphor synthesized by MCG method is promising candidate for solid state lighting applications.