Reddish-orange light emission via combustion synthesized Ba3Y4O9: Sm3+ nanocrystalline phosphor upon near ultraviolet excitation

A highly efficient solution combustion technique involving simple procedure and less energy consumption was adopted to prepare a homogeneous crystalline Ba3Y4O9:Sm3+ down-conversion nanophosphor emitting bright reddish orange light. The structural features of the synthesized nanophosphors were characterized by powder X-ray diffraction (PXRD), scanning electron microscope (SEM), transmission electron microscope (TEM), high resolution transmission electron microscope (HRTEM), selected area energy diffraction (SAED) and energy-dispersive X-ray analysis (EDAX) techniques. Moreover, the photoluminescent features of the nanocrystalline phosphors were described by photoluminescence decay curves, excitation and emission spectra. Upon near-ultraviolet (NUV) excitation (410 nm), the emission spectra demonstrate the most prominent peak at 607 nm due to (4)G(5/2) -> H-6(7/2) transition. The optimum mol% of dopant (Sm3+) ion for doping in this particular host matrix was found to be 3; thus, a concentration quenching (CQ) phenomenon was observed beyond x = 0.03 in the synthesized Ba3Y4(1-x)O9: 4x Sm3+ nanophosphors. The most appropriate reason for CQ mechanism was reckoned to be radiative-reabsorption phenomenon and dipole-dipole (d-d) interactions. The CIE chromaticity coordinates for the optimum nanophosphor were found to lie in orange-red region that confirm its characteristic light emission. The results indicate the promising applications of the synthesized reddish-orange light emitting Ba3Y4O9: Sm3+ nanophosphor in white light emitting diodes (WLEDs).