Persistent Luminescence of ZnGa₂O₄:Cr³⁺ Transparent Glass Ceramics: Effects of Excitation Wavelength and Excitation Power

Persistent luminescence of transparent ZnGa2O4:Cr3+ thin films from colloidal nanoparticles of tunable size

“…The values obtained for the films annealed at 900 ºC are in agreement with those reported in the literature for ZnGa 2 O 4 :Cr powders annealed at similar temperatures. 53,54,55 Trap depths in the ∼0.5−1 eV range, as is the case of our films, enable a progressive release of carriers at room temperature, giving rise to persistent luminescence, as observed here.…”

“…nanoparticles embedded in glass. 53 Subsequently, the maximum of the TSL glow peak is slightly higher than the working temperature for the 900 °C calcined films and therefore gets closer to the optimum temperature compared to 500 °C annealed films. 51 This is in good agreement with the improved persistent luminescence decays obtained for the 900 °C calcined films compared to the 500 °C ones.…”

EPR in glass ceramics

“…A study of persistent luminescence in ZnGa 2 O 4 nanocrystals containing transparent glass ceramics revealed that the same types of Cr 3 + defects are created as in microcrystalline ZnGa 2 O 4 powders [64]. With an increasing annealing temperature, the EPR lines became narrower, indicating less disorder in the surrounding crystal field.…”

“…With an increasing annealing temperature, the EPR lines became narrower, indicating less disorder in the surrounding crystal field. From simulations with SH parameters used for ZnGa 2 O 4 powders [65], five types of Cr 3 + centers were identified, and their relative concentrations could be estimated from the double integral values of simulation curves [64].…”

Rare-earths doped-nanoparticles prepared by pulsed laser ablation in liquids

“…As already known, persistent luminescence is controlled by the defects, which are not only associated with the parti cles size but also with the crystalline quality. Castaing et al have demonstrated, in the ZnGa 2 O 4 :Cr 3+ nano-glass ceramics, the strong effect of the crystalline quality on the persistent properties [97]. Cristoforetti et al also reported that for particles prepared in acetone, enolate anions are formed on the particles surface and that ensures more stability [98].…”