Bi2O3-B2O3-CaF2-EuF3 glass–ceramics for lighting applications

The Bi2O3-B2O3-CaF2-EuF3 (BiBCEu) glass and glass–ceramics were prepared by controlled heat treatment method for orange-red laser sources and characterized through X-ray diffraction, Fourier transform infrared, Raman, transmission electron microscopy, photoluminescence excitation, emission and luminescence decay studies. Up on 396 nm excitation, the BiBCEu glass–ceramics containing Bi3B5O12 and CaF2 nanocrystallites exhibit an enhanced orange-red luminescence through Eu3+:5D0 → 7F2 (616 nm) transition. The radiative parameters such as radiative emission probability rate (AR), luminescence branching ratio (βR) and radiative decay time (τR) were determined using the intensities of Eu3+: 5D0 → 7FJ (J = 1, 2, 4) emission transitions following the Judd–Ofelt theory. The chromaticity coordinates of BiBCEu glass–ceramic heat treated at 575 °C for 10 h are situated in the orange-red region of the CIE diagram. The BiBCEu glass–ceramic synthesized at 575 °C for 10 h has an excellent proficiency for solid state orange-red laser sources.