Chemical synthesis of Lead Iodide nanoparticles for photovoltaic and optoelectronic device applications

In the present study, highly recommended lead iodide (PbI۲) nanoparticles and thin films based on PbI۲ nanoparticles have been prepared for optoelectronics and solar cell applications. PbI۲ is an anisotropic p-type semiconductor with a band gap of ۲.۵۷ eV at room temperature. PbI۲ material has large potential applications in optical detector, digital X-ray imaging, gamma ray detector, etc. PbI۲ layered semiconductor nanoparticles were stabilized using thioglycerol and investigated by Ultraviolet-Visible (UV-Vis) absorption spectroscopy, X-ray Diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS), transmission electron microscopy (TEM) and photoluminescence (PL) spectroscopy. The chemical bath deposition (CBD) method was used to deposit PbI۲ thin films on fluorine-doped tin oxide (FTO) glass substrates. These films were characterized by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), mapping and atomic force microscopy (AFM). Thicknesses of PbI۲ thin films were estimated using a laser profilometer. The blue shift was observed in UV-Vis absorption and PL spectra of PbI۲ nanoparticles. TEM was used to obtain quantitative information on the PbI۲ particle size distribution. Due to the low solubility of PbI۲ in acetonitrile, approximately ۲۰-۳۰ nm sized circular particles are obtained. The variation of ۱۸ Å was observed in the lateral dimensions of PbI۲ nanoparticles. Pb۴fXPS core level appeared at ۱۳۸.۵ eV corresponding to PbI۲. There is no report published wherein the PbI۲ nanoparticles and the PbI۲ thin films were prepared by the aqueous chemical method and the CBD method respectively. In this study, the characterization results of PbI۲ nanoparticles and PbI۲ thin films were better than many other materials.

Keywords:

Synthesis , Characterization , nanoparticles , PbI۲ thin films , Chemical bath deposition method