Structure and luminescence properties of Sr9La(PO4)5(SiO4)F2:Dy3+ single-component white-emitting phosphor for n-UV w-LEDs

Abstract

A single-component white-emitting phosphor Sr9La(PO4)5(SiO4)F2:Dy3+ pumped for n-UV-light emitting diodes was firstly presented by solid state method and the crystal structures, luminescence properties, especially the concentration quenching behaviors were discussed in detail. Accordingly, the quantum efficiencies as well as lifetime studies of Dy3+ in CLPGF phosphor were also carried out. The results revealed that the Sr9La(PO4)5(SiO4)F2:Dy3+ phosphor could be efficiently excited in a broad wavelength ranging near ultraviolet (n-UV) regions, which matched perfectly with n-UV white light emitting diodes (w-LEDs) chips. Under the excitation at 349 nm, the phosphor exhibited three prominent emission peaks in the visible wavelength region located at 483, 578 and 670 nm, which is ascribed to the 4F9/2-6H15/2, 4F9/2-6H13/2 and 4F9/2-6H11/2 transitions of Dy3+, respectively. It was also proved that the dipole-dipole interactions results in the concentration quenching in Sr9La(PO4)5(SiO4)F2:Dy3+ phosphors. Fascinatingly, when the temperature turned up to 150 °C, the emission intensity at 483 and 578 nm was 83.4 and 89.1% of the initial value at room temperature. Additional, the corresponding activation energy ΔE was determined to be 0.16999 and 0.17451 eV, which indicated the excellent thermal stability of the samples. All these findings demonstrated that as-prepared phosphors could act as a high-performance candidate for the application.