Lead Sulfide Quantum Dots in Glasses

Abstract

The size and spatial distribution of PbS QDs in glasses need to be controlled in order to achieve desired optical characteristics. This paper reports on the use of several rare-earth oxides such as Ho2O3, Er2O3, and La2O3 to control the size of PbS QDs in silicate glasses. Additions of rare-earth oxides result in blue shifts of the absorption bands from 1344nm to 930nm, and the wavelengths of PL bands can be controlled between 1421nm ~ 1035nm. Additions of up to 0.8 mol% of Ho2O3 decreased the diameters of PbS QDs from 4.82nm to 3.02nm. The same tendencies were found for both Er2O3 and La2O3 additions, although the size of PbS QDs increased as the size of rare-earth ions increased. It is proposed that clusters of RE-O bonds act as nucleating agents for the precipitation of PbS QDs.