Nanostructures, optical properties, and imaging application of lead-sulfide nanocomposite coatings

Abstract

Lead-sulfide (PbS) nanocrystals were precipitated in nanocomposite coatings after a pre-photo-polymerization followed by a reaction with H2S gas at 25°C for 1 hr. PbS nanocrystalline size and optical absorption increased with decreasing UV energy for prephoto-polymerization and increasing concentration. The absorption onset has a large blue shift from 0,41 eV of the corresponding bulk crystal, resulting from the quantum confinement effect. As a result, coating color changes significantly from deep brown to light yellow depending on coating processing conditions. Partially masking the coatings during pre-photo-polymerization gives rise to different colors, leading to imaging applications of PbS nanocomposite coatings.