Photoluminescent properties and energy transfer mechanism of Tb3+-Ce3+ doped CaSi2O2N2 oxynitride phosphors

The Ce 3+ -Tb 3+ doped CaSi 2 O 2 N 2 phosphors are successfully obtained via conventional solid-state reaction at normal pressure. Broad absorption bands from Ce 3+ are clearly observed in the excitation spectra of CaSi 2 O 2 N 2 :Tb 3+ , Ce 3+ . The emission spectra present a combination of Tb 3+ and Ce 3+ emission bands, and the emission intensity of Ce 3+ is decreased along with the enhancement of the emission intensity of Tb 3+ . The energy transfer from Ce 3+ to Tb 3+ in the CaSi 2 O 2 N 2 host is confirmed to be resonant type via a dipole–dipole interaction mechanism. It is also found that the luminescence intensity of the Tb 3+ -Ce 3+ doped CaSi 2 O 2 N 2 phosphors prepared in N 2 /H 2 atmosphere is stronger than that prepared in pure N 2 .