Resolution of Eu2+ asymmetrical emission peak of SrAl2O4:Eu2+, Dy3+ phosphor by cathodoluminescence measurements

Abstract The green photoluminescence (PL) peak from SrAl2O4:Eu2+, Dy3+ phosphor is normally asymmetrical and tails towards the longer wavelengths. Previous Gaussian de-convolution resulted in two peaks attributed to Eu2+ occupying the two different crystallographic Sr2+ sites. In this letter two resolved peaks through cathodoluminescence (CL) measurements are reported. The intensity degradation upon the phosphor charging when exposed to electron beam reveals additional information about the electronic transitions. The observed peak in the longer wavelength is associated with preferential alignment of one of the Eu2+ d-orbital. The observations are used to modify Clabau et al.'s model of afterglow mechanism.