Tb3+-doped green emitting CaLaB7O13 phosphor: Luminescent properties under UV, and VUV excitation

Impact of Structural Changes on Energy Transfer in the Anion-Engineered Re3+:Y2O3 Through Low-Temperature Synthesis Approach

“…White light-emitting diodes (w-LEDs) have substantially replaced conventional light sources (incandescent and fluorescent lamps) owing to their outstanding features such as low energy consumption, high brightness, high luminous efficiency, and long operational lifetimes . Rare earths (RE 3+ )-doped phosphors for w-LEDs have garnered considerable attention due to their widespread applications in the field of lighting. , Among many RE-doped phosphors, Tb 3+ doped metal oxides are well-known for obtaining green emission. − However, Tb 3+ -doped materials suffer from a lower luminescence due to the weak and narrow absorption cross-section (σ abs ∼ 10 –20 cm 2 ) originating from spin-forbidden electric dipole transitions between 4 f energy levels of Tb 3+ . , To overcome this issue, codoping of Tb 3+ ions with Ce 3+ sensitizers has attracted significant attention due to their high absorption cross-section (σ abs ∼ 10 –19 cm 2 ) in the UV region stemming from the allowed 4 f -5 d transition, shorter luminescence lifetime, and overlapping 5 d energy states of Ce 3+ ions with Tb 3+ 5 D J excited states. − For instance, GdPO 4 :Ce 3+ /Tb 3+ nanorods have been reported to be efficient hosts for the energy transfer from Ce 3+ to Tb 3+ ions with 28% quantum efficiency . The study revealed that the energy transfer depends upon the oxidation state of Ce ions in the host since dispersing codoped (GdPO 4 :Ce 3+ /Tb 3+ ) sample into KMnO 4 (oxidizing agent) solution resulted in significant luminescence quenching due to a change in the oxidation state of Ce from Ce 3+ to Ce 4+ .…”