Structural and luminescent properties of Eu3+-doped GdSrAl3O7 nanophosphor

Abstract

Eu3+-doped GdSrAl3O7 nanophosphor with promising luminescent properties has been synthesized by low-temperature solution combustion synthesis. The structural properties examined by X-ray diffractometer, scanning electron microscopy, and transmission electron microscopy showed that pure tetragonal GdSrAl3O7: Eu3+ red nanophosphor having narrow size distribution in 50–55 nm range could be readily obtained at low temperature 550 °C. The photoluminescent excitation and emission spectra, life time, and concentration effect were studied in detail. Under excitation at 266 nm, Eu3+-doped GdSrAl3O7 nanophosphor revealed weak green emission and strong red emission attributed to 5D1 → 7F1–2 and 5D0 → 7F0–3 transitions of Eu3+ ion, respectively in the region of 525–700 nm. The red emission from 5D0 → 7F2 transition at 616 nm exhibits the highest intensity under the optimized concentration of 10 mol% after which the quenching mechanism became relevant. Quenching behavior of the europium in the GdSrAl3O7 host was explained by nonradiative cross-relaxation phenomenon. Moreover, Eu3+-doped GdSrAl3O7 nanophosphor can generate light from orange to deeper red by properly tuning the concentration of europium ions based on the energy transfer principle.