Nanocrystallization and photoluminescence of Ce/Dy/Eu-doped fluorosilicate glass ceramics

Ce3+–Eu2+–Dy3+–Eu3+-doped fluorosilicate glass ceramics containing orthorhombic CaCeOF3 nanocrystals were prepared by annealing the precursor glass above 640 °C, along with the reduction of Eu3+ → Eu2+. Under near ultraviolet excitation, the emission bands of Eu2+ or Dy3+ were enhanced by several ten or hundred times, owing to energy transfers from Ce3+ to Eu2+ or Dy3+. The glass and glass ceramics emitted warm white light deriving from the blue, yellow and red emission from Eu2+, Dy3+ and Eu3+. Tuning the annealing temperature, the Eu2+/Eu3+ ratio and the warm white Commission Internationale de I’Eclairage (CIE) coordinates can be adjusted. Thus, the present materials can be applied on warm white high power light-emitting-diodes for indoor illumination application.

► Orthorhombic CaCeOF3 nanocrystals were precipitated in the Ce/Dy/Eu doped glass.
► The reduction of Eu3+ →Eu2+ took place along with the annealing process.
► The Eu2+/Eu3+ ratio can be fine adjusted by tuning the annealing temperature.
► ETs from Ce3+ enhanced emission of Eu2+ or Dy3+by several ten or hundred times.
► The glass ceramics emit warm white light with tunable CIE coordination.