Optical properties of silver-doped aluminophosphate glasses

Silver-doped aluminophosphate glasses were prepared by the melt-quenching technique in which silver nanoparticles (NP) of different sizes were embedded upon heat treatment. Optical absorption and photoluminescence spectroscopy were used to study the optical properties of the material before and after thermal processing. Photoluminescence (PL) experiments revealed a broadband emission observed around 420 nm for the non-heat treated samples with a luminescence decay showing a bi-exponential behavior. Temperature dependence PL studies showed a thermal quenching effect on the broadband emission. Our data suggests that the emission is due to single Ag⁺ ions. Optical absorption measurements performed on the heat treated samples allowed for particle size estimation and the evaluation of the thermal stability of the glass system and its attributes as a host for NP inclusion. The nanocomposite showed a dip in the broadband emission of silver ions ascribed to absorption of Ag⁺ ions luminescence by surface plasmons in the silver particles.