Inner energy transfer and its influence on luminescence properties of CaGa2O4:Eu3+ reddish emission phosphors

• CaGa2O4:Eu3+ was firstly reported for photoluminescence phosphors compared with electroluminescence.
• Pure and good red emission was obtained from CaGa2O4:Eu3+ phosphor.
• Inner energy transfer from the host and Eu3+ favored the D0–Fj transitions of Eu3+.

The photoluminescence properties of Eu3+ doped CaGa2O4 phosphors prepared by high temperature solid state reaction method were firstly investigated and analyzed for the difference from the electroluminescence and the potential applications into LED. The experimental results indicated that there exist two strong absorption bands at around 394 nm and 463 nm, which are consistent with the output wavelengths of GaN-based LEDs. The predominant transition of Eu3+ ions originates from the electric dipole transition 5D0–7F2 with the red emission at 617 nm, indicating that Eu3+ ions occupy the sites without inversion symmetry. The optimum concentration of Eu3+-doping was obtained to be 4 mol% and the emission quenching occurred when the content of Eu3+ increased. The inner energy transfer including radiative and non-radiative energy transfer from the host to Eu3+ ions was observed.