Effects of Dy concentration on luminescent properties of SrAl2O4: Eu phosphors

Abstract

SrAl2O4: Eu is a member of family of long lasting phosphors (LLP) and is useful as a luminescent material which emits green light. It is a promising candidate for detecting an element for a visible display of two dimensional radiation distributions. We have investigated effects of Dy doping on optical and structural properties of SrAl2O4: Eu nano phosphors prepared by combustion synthesis technique (CST). The obtained specimens are thoroughly characterized paying particular attention to their structure, composition, morphology and optical properties. The optical properties are presented and discussed in terms of photoluminescence (PL) and electroluminescence (EL). The PL spectra (under the excitation of 365nm) of SrAl2O4: Eu samples with varied concentrations of Dy have wide peaks in visible region, which are attributed mainly to transitions of Eu2+. With increasing concentration of Dy a slight increase in peak intensities is noticed and at a particular concentration intensity gets saturated owing to concentration quenching. The surface morphology and structural properties of SrAl2O4: Eu, Dy phosphors are studied using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The average grain size as calculated using SEM and XRD results lies in nano range.