Photoluminescence Investigations of the Near White Light Emitting Perovskite Ceramic SrZrO3:Dy3+ Prepared Via Gel-Combustion Route

Trivalent dysprosium-doped strontium zirconate perovskite (SrZrO3) phosphors were prepared by gel-combustion synthesis using citric acid as fuel and ammonium nitrate as oxidizer. X-ray diffraction patterns confirmed the formation of orthorhombic phase of SrZrO3 with minor impurity, which completely disappears at high temperature. The morphological investigation was carried out using scanning electron microscopy (SEM). Photoluminescence studies showed that no emission from the host is observed, indicating the efficient energy transfer from the ZrO32- group to Dy3+ ions. The emission line is purely because of f-f transitions of Dy3+. Moreover, these phosphors predominantly exhibit near white light emission, when excited by 229nm UV light due to strong (F9/2H13/2)-F-4-H-6 transition at 577nm (yellow), strong (F9/2H15/2)-F-4-H-6 transition at 482nm (blue), and weak (F9/2H9/2)-F-4-H-6 transition at 677nm (red). Enhancement in emission intensity was observed with increase in the annealing temperature of the phosphor. The CIE chromaticity coordinates of the SrZrO3:Dy3+ phosphors were observed to fall in the white light domain of the chromaticity diagram, which indicate that such fine tuning might be possible after varying the temperature of annealing.