Synthesis and Characterization of Colloidal PbS Quantum Dots in Gelatin

Abstract

Colloidal solutions of lead sulphide (PbS) quantum dots (QDs) stabilized in gelatine were obtained using a novel simple method. Nanoparticle sizes were tuned during the synthesis by means of reaction temperature. In addition, the effect of acidity of solution, of reagents concentrations and of S to Pb molar ratio was investigated. Transmission electron microscopy (TEM) and energy-dispersive X-ray spectroscopy (EDX) was used to characterize the size and composition of PbS nanoparticles. Also, the peculiarities of photoluminescence (PL) spectra of PbS QDs in gelatine were studied. It was observed that PL spectrum consists of a relatively narrow excitonic band with the maximum located at 0.95– 1.3 eV depending on the QDs size.