Luminescent properties of single Dy3+ ions activated Ca3Gd7(PO4)(SiO4)5O2 phosphor

• A single-phase white-emitting phosphor Ca3Gd7(PO4)(SiO4)5O2: Dy3+ was obtained.
• Energy transfer phenomenon from Gd3+ to Dy3+ in the phosphor was observed.
• The concentration quenching mechanism of Dy3+ ions was dipole–dipole interaction.
• The phosphor is a promising candidate for UV-based white light illumination.

Single Dy3+ ions activated Ca3Gd7(PO4)(SiO4)5O2: Dy3+ (CGPS: Dy3+) phosphors were successfully synthesized by solid-state reaction method. The X-ray diffraction results confirm that the as-prepared CGPS: Dy3+ samples are pure CGPS hexagonal phase. Moreover, the substitution of Dy3+ for Gd3+ in CGPS host leads to the major diffraction peaks moving towards larger angle due to a smaller ions radius of Dy3+ than Gd3+. Upon excitation of 275 nm and 349 nm ultra violet (UV) that are respectively attributed to 8S → 6I transitions of Gd3+ and 6H15/2 → 6P7/2 transition of Dy3+, the characteristic emission of Dy3+ ions such as 4F9/2 → 6H15/2 (480 nm) and 4F9/2 → 6H13/2 (572 nm) can be clearly observed. A high ratio of yellow emission to blue emission (Y/B) implies that Dy3+ ions prefer to occupy low-symmetry 6h (Cs) sites in CGPS matrix. Therefore, white light can be obtained from Dy3+ mono-doped CGPS: Dy3+ phosphor with CIE chromaticity coordinates of (x = 0.328, y = 0.343). By calculation, the mechanism of concentration quenching between Dy3+ ions is electric dipole–dipole interaction. In addition, the energy transfer (ET) from Gd3+ to Dy3+ can also be observed. These results suggest that CGPS: Dy3+ phosphors could be a promising candidate for UV-based white light illumination.

A novel Ca3Gd7(PO4)(SiO4)5O2: Dy3+ phosphors were synthesized by the conventional solid-state reaction route. Under the excitation of 275 nm and 349 nm ultra violet respectively due to the 8S → 6I transition of Gd3+ in the host and 6H15/2 → 6P7/2 transition of the activator Dy3+, the two emission spectra have similar profiles confirming that the energy transfer from Gd3+ to Dy3+ exists in the Ca3Gd7(PO4)(SiO4)5O2: Dy3+ phosphor. The phosphor emits white light with Commission International de I’Eclairage in 1931 (CIE 1931) chromaticity coordinate of (0.328, 0.343), which is quite close to the CIE ideal white light (0.33, 0.33).Figure optionsDownload high-quality image (92 K)Download as PowerPoint slide