Petit, Laeticia
[Author];
García, Nicolás
[Author];
Vuori, S.
[Author];
Byron, Hanna
[Author];
Van der Heggen, David
[Author];
Smet, Philippe F.
[Author];
Lastusaari, M.
[Author]
Near-Infrared Rechargeable Glass-Based Composite with Green Persistent Luminescence from New Yb3+, Tm3+ Co-Doped Oxyfluorophosphate Glasses
Description:
Materials with persistent luminescence are of great interest for various applications. However, their afterglow is mainly obtained after exposure to UV-visible light, limiting their use in biological applications involving deep tissue. Here, the fabrication of a Yb3+, Tm3+ co-doped bioactive oxyfluorophosphate glass-based composite, that exhibits green persistent luminescence after being charged with near-infrared light, is demonstrated for the first time. The mechanism responsible for the green afterglow after near-infrared illumination is also unveiled. The composite is prepared using a modified direct doping process to limit the evaporation of fluorine during melting. Intense blue up-conversion emission is obtained by optimizing the Yb2O3 concentration rather than by heat-treating the glass into a glass-ceramic. Indeed, although a heat treatment of the glass promotes the volume precipitation of Yb3+, Tm3+ co-doped CaF2 crystals, the intensity of the blue up-conversion emission is lower in the highly Yb3+-concentrated glass-ceramic due to reverse energy transfer from Tm3+ to Yb3+. By combining the Yb3+ and Tm3+ ions added in the glass matrix, with commercial SrAl2O4:Eu2+,Dy3+crystals, green afterglow from the composite can successfully be obtained after charging with near-infrared light, clearly demonstrating that the newly developed glass-based composites are promising as an optical battery for biomedical applications