Enhanced UVC upconversion luminescence in Pr3+-doped eulytite-type phosphates
Alexander Grippa, Nadiia Rebrova, Patrycja Zdeb-Stańczykowska, Przemysław J. Dereń
Abstract:
UVC radiation's strong antiseptic properties make it ideal for water and surface decontamination, underscoring the need for new UVC-generating materials. In this work, Pr3+-doped Ba3La(PO4)3 and Ba2.5La1.5(PO4)2.5(SiO4)0.5 phosphors were synthesized via the Pechini method, and their structural and luminescent properties were investigated. Both compounds crystallize in a cubic eulytite-type structure and exhibit stronger 1D2 → 3H4 (575–645 nm) emission than the 3P0 → 3H4 (465–505 nm) transition. Under UV excitation, efficient 5d–4f emission is observed, while 444 nm laser excitation induces UVC upconversion via a two-photon process dominated by excited-state absorption (ESA). Optimal upconversion occurs at 1.5 % Pr3+ doping, with Ba2.5La1.5(PO4)2.5(SiO4)0.5 showing ∼30 % higher intensity than Ba3La(PO4)3 due to enhanced local disorder and crystal field effects. These materials outperform YPO4:Pr3+ phosphate in upconversion emission, highlighting their potential for use in UVC-emitting devices.
