Simultaneous influence of dual sensitizers on photo-physical properties in Dy3+ activated YVO4 phosphors

Abstract

A series of doubly sensitized and Dy3+ activated YVO4 (YVO4: 3at%Dy3+ , 7at%Bi3+ , xMn2+) phosphors have been synthesized adopting the high temperature solid state reaction route. The detailed study on the structural, optical and photo-physical properties have been carried out through various analytical techniques to investigate the simultaneous effect of activator and sensitizers on the host matrix. Reitveld refinement of the X-ray Diffraction (XRD) profiles with low χ2 values authenticate better crystallinity with a tetragonal zircon type structure. The microstructural particle morphology has been explored through scanning electron microscopy (SEM) and the physio-chemical purity has been probed through the vibrational spectroscopy analysis. The emission spectral profile reveals that the Bi3+ sensitized phosphor exhibits broad emission band in the blue-violet region corresponding to the 3P1→1S0 transition along with the yellow emission of Dy3+ ( 4F9/2→6H13/2). Furthermore, on substituting Mn2+, a far red emission is observed with an efficient energy transfer to the Dy3+ ions, resulting in enhancement of the emission intensity. Thus, Bi3+ and Mn2+ doping reflects in broadening the emission spectra on a wide range of visible spectra, thereby increasing the applicability of the said phosphors.