In situ-monitored enhancement and quenching effect of Cu nanoclusters on Sm3+ photoluminescence in glass

An assessment of the influence of heat treatment temperature and retention time on the optical properties of a Cu⁺ and Sm³⁺ co-doped phosphate glass of interest to photonic applications is reported. Particularly, the enhancement of the orange-red photoluminescence (PL) from Sm³⁺ ions has been realized in the glass through the development of non-plasmonic Cu clusters. It was exposed during an in situ isothermal treatment wherein optical absorption and PL were monitored together in real time. Following the PL increase, a drop in the Sm³⁺ emission intensity was produced concurring with the appearance of Cu nanoparticles (NPs) exhibiting the surface plasmon resonance. Hence, the connection between energy donor (sensitizing) effects of small Cu clusters and the energy acceptor (quenching) character of Cu NPs is supported. It is the first time to the author's knowledge that the enhancement of Sm³⁺ luminescence via Cu clusters embedded in glass is indicated.