Photoluminescent properties of novel red-emitting GdSr2AlO5:Eu3+ phosphors

Red-emitting GdSr2AlO5:Eu3+ phosphors were synthesized by a modified citrate sol-gel route. The tetragonal phase of the GdSr2AlO5:Eu3+ phosphors were confirmed by measuring the XRD patterns. The photoluminescence excitation (PLE) and emission (PL) properties of these phosphors were carried out to analyze their emission performance. The PLE spectra of the GdSr2AlO5:Eu3+ phosphors exhibited the high intense charge transfer band and typical f-f transitions of Eu3+ ions. The PL spectra of GdSr2AlO5:Eu3+ phosphors unveiled the red emission with the band centered at 625 nm, which is originated from the 5D0 → 7F2 transition. The Eu3+ ion concentration in the GdSr2AlO5 host lattice was optimized with respect to the 5D0 → 7F2 transition intensities, and was found to be at 4 mol%. The decay curves data of the GdSr2AlO5:Eu3+ phosphors were well fitted with a single exponential function.