The influence of silver ion exchange on the formation and luminescent properties of lead sulfide molecular clusters and quantum dots

Resumo

PbS molecular clusters and quantum dots are formed by heat treatment in fluorophosphate glasses of the Na₂O₃–Р₂O₅–Ga₂O₃–AlF₃–ZnO(S)–PbF₂ system with different lead concentrations. PbS molecular clusters are characterized by optical absorption in the range of 300–800 nm and low quantum yields, which decrease from 8.9 to 2.7% with a semiconductor component concentration. It is shown that the parameters of formation of quantum dots luminescing in the wavelength range of 1000–1500 nm are considerably different at different semiconductor component concentrations. The influence of silver ion exchange on the formation of PbS nanoparticles is studied. Introduction of silver stimulates the growth of molecular clusters, which is seen in the absorption spectra. A possible mechanism of interaction of silver nanoparticles with PbS quantum dots is presented.