NaSrVO4:Sm3+ - An n-UV convertible phosphor to fill the quantum efficiency gap for LED applications

The structural and luminescent properties of Sm3+ doped NaSrVO4 phosphors prepared by the combustion method were investigated. The phosphors were characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), photoluminescence spectroscopy (PL) and diffuse reflectance spectroscopy (DRS). NaSrVO4 crystallized into the monoclinic phase with P2(1/n), space group. The Debye Scherrer's formula and Williamson-Hall (W-H) plot were used to determine the average crystallite size of the phosphors. Upon near-UV excitation, the phosphor gives the characteristic orange red emission ascribed to the intra-4f-shell (4)G(5/2) to H-6(J) (J=5/2, 7/2, 9/2, 11/2) transitions of Sm3+. The diffused reflectance spectra of the phosphors were used to calculate the optical band gap (;) of the material, which was estimated to be 3.58 eV. The chromaticity coordinates (x=0.61, y=0.39) of the phosphors further validated the orange red emission of the material. This phosphor may be used as near ultraviolet (n-UV) convertible orange red emitting phosphor in light emitting diodes (LEDs). (C) 2015 Elsevier Ltd and Techna Group S.r.l. All rights reserved.