Synthesis and characterization of silica–lead sulfide core–shell nanospheres for applications in optoelectronic devices

Nanoscale miniaturization of chalcogenide semiconductors such as lead sulfide (galena) can generate interesting quantum confinement effects in the field optoelectronic applications. In this work, we developed a process order to obtain SiO2 nanospheres coated with Galena, denominated core–shell system; is based on Stöber’s method, where magnetic stirring was replaced by an ultrasonic bath achieve well rounded and highly stable silica nanoparticles diameters average 70 nm. The PbS shell cover presents thickness 10 nm around. nanostructures’ chemical composition, morphology, optical properties were determined transmission electron microscopy UV–Vis spectroscopy. As result, nanoshells correspond cubic PbS, presenting some interplanar distances 2.95 Å 3.41 Å; nanoshell also shown spectrum shift toward blue remarkable increase 3.75 eV its band gap, compared bulk value. composition studied energy scattering spectroscopy X-ray photoelectron analysis.