Effect of Silver Ion‐Exchange on the Precipitation of Lead Sulfide Quantum Dots in Glasses
This article reports the effect of Ag+ ion‐exchange on the precipitation of PbS quantum dots (QDs) in silicate glasses. The glasses were subjected to ion‐exchange
in AgNO3 salt melts at 260°C for 60 s. Ag nanoparticles (NPs) and PbS QDs precipitated after heat treatment at temperatures
of 440°C–460°C for 10 h. Photoluminescence wavelength λPL of PbS QDs was longer (~1525 ≤ λPL ≤ ~1580 nm) in Ag+
ion‐exchanged regions than in Ag+‐free regions (~1030 ≤ λPL ≤ ~1200 nm). Average diameter D of PbS QDs estimated by calculation
and TEM images was larger in Ag+ ion‐exchanged regions (~5.2 ≤ D ≤ ~5.5 nm) than in Ag+‐free regions (~2.4 ≤ D ≤ ~3.3 nm).
Ag NPs that formed during heat treatment provided the sites for heterogeneous nucleation of PbS QDs and promoted the precipitation of PbS QDs in glasses.