Photoluminescence and afterglow behavior of Eu2+, Dy3+ and Eu3+, Dy3+ in Sr3Al2O6 matrix

This paper reports the photoluminescence and afterglow behavior of Eu2+ and Eu3+ in Sr3Al2O6 matrix co-doped with Dy3+. The samples containing Eu2+ and Eu3+ were prepared via solid-state reaction. X-ray diffraction (XRD), photo luminescent spectroscope (PLS) and thermal luminescent spectroscope (TLS) were employed to characterize the phosphors. The comparison between the emission spectra revealed that Sr3Al2O6 phosphors doped with Eu2+, Dy3+ and Eu3+, Dy3+ showed different photoluminescence. The phosphor doped with Eu3+, Dy3+ showed an intrinsic f-f transition generated from Eu3+, with two significant emissions at 591 and 610 nm. However, the phosphor doped with Eu2+, Dy3+ revealed a broad d-f emission centering around 512 nm. After the UV source was turned off, Eu2+, Dy3+ activated Sr3Al2O6 phosphor showed excellent afterglow while Eu3+, Dy3+ activated phosphor almost showed no afterglow. Thermal simulated luminescence study indicated that the persistent afterglow of Sr3Al2O6: Eu2+, Dy3+ phosphor was generated by suitable electron traps formed by the co-doped rare-earth ions (Dy3+) within the host.