PbS nanoparticles in Langmuir–Blodgett films: kinetics of formation and growth

Abstract

The formation and growth of lead sulfide nanocrystals in lead stearate Langmuir-Blodgett (LB) films are investigated by optical absorption spectroscopy. Kinetics of the concentration changes of lead ions in the different states formed during the growth process, as well as the evolution of the nanocrystal average size versus growth time, are studied. A nonlinear dependence of the nanoparticle growth rate versus time is found. The idea of diffusive decomposition of solid solutions is used to analyze the experimental results. It is shown that high concentrations of metal ions at the interfaces of monolayers of LB films, as well as diffusion restrictions of mass-transfer processes, play a decisive role in the formation and growth of nanocrystals in ordered organic matrices.