Formation of lead iodide nanoparticles using the sol–gel method and their applications

Lead iodide (PbI${}_2)$ nanoparticles in silica have been synthesized using the sol–gel method. The aqueous method of synthesis has been used for undoped PbI₂ nanoparticles. These nanoparticles have been stabilized using thioglycerol acting as the capping agent. The narrow-sized PbI₂ nanoparticles have been obtained, which are characterized by size-dependent properties. The PbI₂ nanoparticles have been characterized and their properties have been investigated by using various experimental techniques like Ultraviolet–Visible (UV–Vis) Absorption Spectroscopy, X-ray Diffraction (XRD), Transmission Electron Microscopy (TEM), X-ray Photoelectron Spectroscopy (XPS), Photoluminescence (PL), Atomic Force Microscopy (AFM), etc. The lateral dimension of PbI₂ nanoparticles in silica varies from 9 Å to 27 Å. PbI₂ thin films were deposited on silicon wafers by using the dip coating method and analyzed by using various characterization techniques like Scanning Electron Microscopy (SEM), Energy Dispersive Analysis by X-rays (EDAX), Mapping, etc. The aim of this work is to synthesize PbI₂ nanoparticles with a size less than or comparable to the Bohr diameter of the exciton. The characterization results showed that the cluster size increases with the increasing film thickness and by the heat treatment in air atmosphere. The PbI₂ nanocrystals embedded in silica films have been studied in this paper. The PbI₂ nanoparticles and the PbI₂ sol–gel thin films can be used in optoelectronic device applications and chemical industrial applications. To the best of our knowledge, there are no studies on the synthesis of PbI₂ nanoparticles in silica using the sol–gel route and on the preparation of PbI₂ thin films using the dip coating method.