Photoluminescence and thermoluminescence studies of CaAl₂O₄:Dy³⁺ phosphor

Abstract

Calcium aluminate phosphors activated by Dy(3+) have been prepared by a combustion method at a temperature of 600°C. Photoluminescence (PL) and thermoluminescence (TL) properties of gamma-irradiated Dy-doped calcium aluminate were investigated. The PL spectrum shows a broad peak around 488 nm and 573 nm, under 347 nm excitation. Thermoluminescence studies were performed for different concentrations of Dy. Optimum intensity of photoluminescence was found for 0.02 mol% concentration of Dy. It was found that initially the peak TL intensity increases with increasing concentration of Dy in the CaAl2O4 host, attains a maximum value for 0.05 mol% concentration and decreases with further increase in the doping concentration due to concentration quenching.

Photoluminescence and afterglow of Dy3+ doped CaAl2O4 derived via sol–gel combustion

“…It is known that Dy 2 O 3 can be dissolved into dilute HNO 3 solution to form Dy (NO 3 ) 3 . 9 In this work, Dy 2 O 3 is used as a starting material to provide the source of Dy 3+ because a tiny amount of Dy 2 O 3 can be dissolved into the aqueous solution of Al(NO 3 ) 3 and urea after stirring with a magnetic bar for a couple of hours at a temperature higher than 20 °C. Since the synthesis process occurs at high temperatures generated by the self-propagating combustion, this method is ideally suited for the production of refractory materials including ceramics CaAl 2 O 4 .…”

“…6 For aerglow materials, the processes of charged carrier excitation, migration, trapping, detrapping, and radiative recombination are critically important to understand their aerglow properties. [7][8][9] For example, long aerglow can be achieved at room temperature only when traps have an appropriate activation energy somewhere around 0.65 eV whereas shallow traps (E # 0.4 eV) and deep traps (E > 2 eV) are not favorable because they can be emptied either easily or with difficulty at room temperature. 7 Up to date, only a single report exists on the aerglow of CaAl 2 O 4 :Dy 3+ , leaving the processes of charged carrier excitation, migration, trapping and detrapping not fully revealed.…”

Thermoluminescence properties of Eu‐doped and Eu/Dy‐codoped Sr2Al2SiO7 phosphors

“…However, part of the excitation energy is stored when electrons and holes are trapped in the trap levels. When the sample is heated, the thermal energy excites the filled traps to release charge carriers and is transferred through the host to the Eu 2+ , followed by the recombination of electrons and holes in the luminescence centers; this gives rise to luminescence . Dy 3+ ions create traps that enhance the TL properties .…”

“…When the sample is heated, the thermal energy excites the filled traps to release charge carriers and is transferred through the host to the Eu 2+ , followed by the recombination of electrons and holes in the luminescence centers; this gives rise to luminescence. [19,20] Dy 3+ ions create traps that enhance the TL properties. [5] In the case of an UV-irradiated sample, a lower temperature peak was found, which represents the formation of shallow traps.…”

Synthesis and Characterization of CaAl2O4: Dy3+ and CaAl2O4: Sm3+ Phosphor Powders

“…The PL emission spectra show two strong bands at 484 nm and 577 nm, and two minor bands were observed at 667 nm and 757 nm. The major emission band is attributed to a typical 4 F 9/2 → 6 H 15/2 and 4 F 9/2 → 6 H 13/2 transitions of Dy 3+ ions [7,14,15].…”