Photoluminescence and Thermoluminescence Studies of Dysprosium (Dy3+) Doped Zinc Aluminate Nanophosphor (Zn0.97Al2O4:0.03Dy)

Abstract

In the present paper, we have reported zinc aluminate (ZnAl2O4) doped with 0.03 mol. % of dysprosium (Dy 3+ ) nanophosphor with general formula Zn(1 -x)Al2O4:x(x  0.03 mol. %)Dy for its luminescence properties and applications. Using urea as fuel, ZnAl2O4 doped with dysprosium (Dy 3+ ) nanophosphor was prepared by the combustion method. The synthesized nanophosphors were characterized with XRD, TEM, SEM with EDS and FTIR spectroscopy. From XRD studies, the average crystallite size was found to be 18.10 nm with space group Fd 3 -m and lattice parameters a  b  c ~ 8.100 Å. The selected area electron diffraction (SAED) revealed concentric circles which are due to polycrystallinity. The two peaks at 652.10 cm -1 and 545.19 cm -1 observed in FTIR spectroscopy correspond to aluminate (AlO6), which indicates the formation of Zn0.97Al2O4:0.03Dy nanophosphor. For photoluminescence (PL) properties, a Xe lamp with 360 nm wavelength was utilized as an excitation source for the measurement. The excitation and emission spectra were evaluated in the range of 200 to 400 nm and 400 to 600 nm, respectively. An excitation peak at 305 nm was observed. For the excitation wavelength (ex = 305 nm), emission spectra were recorded at 476 nm and 574 nm. For thermoluminescence (TL), the sample was pre-irradiated with high energy X-rays under Elekta Synergy radiation generating machine with a dose ranging from 500-1000 Gy. The kinetic parameters like activation energy and frequency factor were calculated from the TL glow curve. The results indicate that Zn0.97Al2O4:0.03Dy could be a potential candidate as a blue-emitting diode and a high radiation passive dosimeter.