Tunable photoluminescence properties of nano-sized Zr1-xO2:xDy3+ phosphors

High-quality nano-sized Dy3+-doped ZrO2 phosphors were synthesized by the solution combustion method. The structural, morphological and photoluminescent properties of these new phosphors were studied with Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy, X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), and photoluminescence spectroscopy, with an emphasis placed on the Dy3+, used as an activator, and annealing temperature. The incorporation of the Dy3+ used as an activator and annealing temperature substantially affected the crystal structure of Zr1-xO2:xDy3+ (0.0001 ≤ x ≤ 0.01) phosphors. The low Dy3+ contents (0.0001 ≤ x ≤ 0.0005) and the high annealing temperature (1100 °C) induced the formation of the monoclinic phase (m-ZrO2) rather than the tetragonal phase (t-ZrO2). The Zr1-xO2:xDy3+ phosphors predominantly exhibited near white light emission under 354 nm excitation owing to the 4F9/2 → 6H15/2 (blue) and 4F9/2 → 6H13/2 (yellow) transitions of Dy3+. The CIE chromaticity coordinates of the Zr1-xO2:xDy3+ phosphors were observed to fall in the near white light domain. The studied Zr1-xO2:xDy3+ is a promising single-phase white-light emitting phosphor for LEDs.