Structure and spectral properties of Dy doped CaYAlO single crystal.

A 2 at.% Dy: CaYAlO single crystal was grown successfully. The electronic structures of Ca/Y mixed sites in CaYAlO were investigated using first-principles based on density functional theory. The effects of Dy doping on the structural parameters of host crystal were studied using XRD pattern. The optical properties including absorption spectrum, excitation spectrum, emission spectra and fluorescence decay curves were thoroughly investigated. The results show that the Dy: CaYAlO crystal could be pumped by the blue InGaN and AlGaAs or 1281 nm laser diodes. Furthermore, an intense 578 nm yellow emission was obtained directly under excitation at 453 nm, meanwhile, evident mid-infrared light emitting was observed by 808 or 1281 nm laser excitation. The fitted fluorescence lifetimes of F and H levels were about 0.316 ms and 0.038 ms, respectively. It can be concluded that this Dy: CaYAlO crystal could simultaneously act as a promising medium for both solid-state yellow and mid-infrared laser outputs.