A novel Al3+ co-doped Dy3+: CaLaGa3O7 phosphor: Preparation, structure and luminescent properties

Novel Al3+ co-doped Dy3+: CaLaGa3O7 (abbr. as Dy, Al: CLGO below) phosphors were synthesized successfully by high-temperature solid-state method. The influence of Al3+ co-dopant was studied through XRD and photo-luminescence (PL) measurements. XRD results did not reveal an influence of Dy/Al singly/co-doping on the structural properties of CLGO crystal. The optical measurements showed that all the produced phosphors can be excited by 348 nm LD. Under the excitation at 348 nm, the phosphors exhibit typical transitions of Dy3+ ions, which emit strong yellow emissions at 574 nm corresponding to the transition of 4F9/2-+ 6H13/2. By comparing the obtained spectral parameters, 2 at.% Dy3+ and 10 at.% Al3+ are determined as the optimal concentration. Moreover, the optimal phosphor composition 0.02Dy, 0.1Al: CLGO presents an internal quantum efficiency (IQE) of 35.06% and external quantum efficiency (EQE) of 11.07%. In addition, the color coordinates of the CIE 1931 indicated that the 0.02Dy, 0.1Al: CLGO phosphor could be regarded as a valuable yellow phosphor for light -emitting diode applications