Gold-assisted enhancement of the luminescence of Mn²⁺ ions induced by silicon in phosphate glass

This Letter reports the first investigation on the influence of gold on the photoluminescence (PL) of Mn²⁺ ions in phosphate glass incorporated via silicon. The glasses were prepared by melting and characterized by X-ray diffraction, optical absorption, and PL spectroscopy with decay dynamics and time-resolved assessment. While silicon-induced defects produced a new Mn²⁺ excitation band around 255 nm, gold co-doping augmented it. By exciting Si-defects at 255 nm, sensitized Mn²⁺ PL around 640 nm was observed, which was enhanced by gold. Resonantly-excited at 360 nm, the Mn²⁺ PL dynamics was analyzed in the context of a bi-exponential decay in connection with interacting and isolated Mn²⁺ ions. Further, a third fast component became prominently manifested with gold under 255 nm excitation. From time-resolved spectra, it was suggested to be linked to the influence of Au particles on luminescent defects.