Near-Green-Emitting Tb3+-Doped Transparent Glass Ceramics Containing Ba2LaF7 Nanocrystals for Application in White Light-Emitting Diodes

Abstract

Tb3+-activated transparent glass ceramics containing Ba2LaF7 were successfully synthesized by a conventional melt–quenching technique, and the glass ceramics displayed a near-green emission under near-ultraviolet excitation. Differential scanning calorimetry and X-ray diffraction were used to monitor the evolution and microstructural changes in the prepared glass specimens. The transparency levels of the glass ceramics remained high with increasing treatment temperatures from 640 to 690°C. Investigations on the luminescence properties of the glass ceramics revealed that Tb3+ ions were gradually incorporated into the precipitated fluoride crystalline phase. After heat treatment at 640°C for 2 h, major emission was observed at 543 nm owing to 5D4 → 7F5 transition of Tb3+ under 373-nm excitation. Current findings indicate that the prepared materials have potential as replacements to commonly employed green phosphors in white light-emitting diodes. Additionally, the decay lifetimes of Tb3+ ions at 543 nm under 373-nm excitation were studied.