Ce3+-activated Ca8Zn(SiO4)4Cl2: A novel near-ultraviolet converting blue-emitting chlorosilicate phosphor for white light-emitting diodes

• Novel chlorosilicate phosphors Ca8-xZn(SiO4)4Cl2: xCe3+ were synthesized.
• The phosphors exhibit bright blue emission under 360 nm excitation.
• The concentration quenching mechanism of Ca8-xZn(SiO4)4Cl2: xCe3+ was confirmed.
• The thermal quenching behavior of Ca7.97Zn(SiO4)4Cl2: 0.03Ce3+ was investigated.
• Our phosphors are promising to develop possible applications for white LEDs.

A series of Ce3+-activated chlorosilicate phosphors, Ca8-xZn(SiO4)4Cl2: xCe3+, was firstly synthesized by solid-state reactions. The crystal structure and luminescence properties of the phosphors, as well as their thermal luminescence quenching capabilities and CIE chromaticity coordinates were systematically investigated. Studies revealed the incorporation of Ce3+ into 8-coordinated Ca site, thereby favoring the novel blue luminescence corresponding to the electric-dipole allowed 4f°5d1–4f1 transition of the Ce3+ ions. Furthermore, the dipole-dipole interaction was dominantly involved in the mechanism of concentration quenching of Ce3+ in the phosphors, and the activation energy for thermal quenching (ΔE) was calculated to be 0.17 eV. Compared with the commercial BaMgAl10O17: Eu2+ phosphor, the composition-optimized Ca7.97Zn(SiO4)4Cl2: 0.03Ce3+ showed a preferable light yield with chromaticity coordinates of (0.156, 0.028) and color temperature of 1896 K. Because of the strong absorption in the near-ultraviolet region and the intense blue emission peaking at 411 nm, our developed phosphors exhibit great potential for use as the promising blue-emitting phosphors for white light-emitting diodes.