Color temperature tunable of Dy3+-doped LaPO4 nanorods prepared via hydrothermal method for white LEDs applications

• Published in: Optical materials 2018-10, Vol.84, p.852-863
• Main Authors: Hamraoui, K., Ferhi, M., Horchani-Naifer, K., Ferid, M.
• Format: Article
• Language: English
• Subjects: Color temperature; Hydrothermal method; LaPO4:Dy3; Nanorods; White LED
• ISSN: 0925-3467; 1873-1252
• DOI: 10.1016/j.optmat.2018.08.014

Nano-powders of La(1-x)DyxPO4 with rod-like morphology have been synthesized via hydrothermal method and characterized by X-ray diffraction, TEM, FTIR and Raman spectroscopy. The X-ray diffraction patterns collected for the prepared materials indicated the high purity of crystalline phase with a monoclinic structure. Photoluminescence properties have been investigated based on excitation and emission spectra, decay curves and chromatic coordinates. The emission spectra show a broad blue band ascribed to the transitions from the excited levels 4I11/2, 4I13/2, 4I15/2 and 4F9/2 to the fundamental levels 6H15/2. A yellow band related to the 4F9/2―›6H13/2 transition has been observed at 573 nm. The luminescence intensities ratio and lifetimes have been found to be dependent on the concentration of Dy3+ ion and the excitation wavelength. The decay curves present double exponential shape for all concentration of Dy3+. The yellow-to-blue emission intensity ratios and CIE chromaticity coordinates have been used to estimate the color of the emitted light. A high-quality of white light with three-color temperature (Warm, Natural or Daylight, Cool) has been obtained from a single emitting phosphor, LaPO4:Dy3+. The improved emission lifetimes and color temperature are suitable for application in the white light LED devices. Different color temperature of the white light can be obtained from a single phosphor LaPO4 doped Dy3+. These emissions can be tuned by modifying the Dy3+ concentration and wavelength excitation. This phosphor has great potential for white LEDs. [Display omitted] •LaPO4:Dy3+ nanorods phosphors were synthesized through hydrothermal method.•Phosphors are identified via XRD, FTIR, Raman and TEM.•Excitation, emission spectra, life time and chromatic coordinates of LaPO4:Dy3+.•A potential single phosphor for different color temperature white LEDs.•Tuning color temperature by controlling the Dy3+ content and excitation wavelengths.