Photoluminescent Properties and Energy Transfer Mechanism of Color‐Tunable CaSi 2 O 2 N 2 :Ce 3+ , Eu 2+ Phosphors

Oxynitride‐based phosphors CaSi 2 O 2 N 2 codoped with Ce 3+ and Eu 2+ were prepared in this study. Broad Ce 3+ excitation spectra ranging from 200 to 500 nm were found for CaSi 2 O 2 N 2 :Ce 3+ , Eu 2+ phosphors. The emission bands consisted of Ce 3+ and Eu 2+ emission peaks. When the Eu 2+ concentration increased, the emission intensity of Ce 3+ decreased along with the enhancement in the Eu 2+ emission intensity. The energy transfer from Ce 3+ to Eu 2+ occurred effectively in CaSi 2 O 2 N 2 :Ce 3+ , Eu 2+ with a dipole–dipole interaction. The increased Eu 2+ concentration led the emitting colors of the prepared phosphor to shift from blue to green region. Increasing the temperature caused the emission intensity to decrease monotonously due to the thermal quenching effects.