Multisite luminescence of blue emitting phosphor (Sr_1-xCe_x)₃Si₁₃Al₃O₂N₂₁

We studied the luminescent properties of Ce³⁺-doped Sr₃Si₁₃Al₃O₂N₂₁ phosphor. We found that Ce³⁺ acts as a luminescence center for blue emission by substituting Sr in the host material. Its internal quantum efficiency is larger than 0.80 under excitation by UV and near-UV light, which shows that this material is suitable for UV- and near-UV-excited white LEDs. Its broad emission spectrum is also attractive for high-color-rendering white LEDs. In order to reveal the origin of its asymmetric photoluminescence (PL) spectra, we measured photoluminescence excitation (PLE) spectra and luminescent decay curves at different monitoring wavelengths. We found that the photoluminescence properties of this material reflect the three different bands which correspond to Ce³⁺ occupying the three different Sr sites of the host material.