Direct Imaging of the Distribution of Nd3+ Ions in Glasses Containing PbS Quantum Dots.

The influence of Nd³⁺ ions was investigated on the precipitation and optical properties of PbS quantum dots ( QDs) inside silicate glasses. The diameters of the PbS QDs decreased as the concentration of Nd³⁺ in the glass increased as evidenced by blue shifts in the absorption and photoluminescence spectra. Electron energy loss spectroscopy shows that Nd³⁺ ions exist preferentially inside the PbS nanocrystals rather than in the glass matrix. We postulate that Nd-O clusters are preserved during heat treatment and serve as nucleation sites for PbS crystals. No change in the local bonding scheme of the Nd³⁺ ions was observed following heat treatment. [ABSTRACT FROM AUTHOR]