Effects of Thickness on Optical and Structural Properties of Lead Sulphide (PbS) Thin Film Prepared by Chemical Bath Deposition (CBD)

Abstract

Nanocrystalline PbS thin films were deposited on glass substrates with various deposition times using chemical bath deposition technique. PbS thin films were prepared by using a solution of Lead nitrate and thiourea by using NaOH salt as a complexing agent and ammonia solution as a pH adjuster at 65 0 C. The study was carried out for thickness in the range of (0.16-1.03m). The structural properties were carried out by X-ray diffraction (XRD). The X-ray diffraction patterns reveal that the films exhibit the cubic face centered structure. The crystalline sizes of the films increased with increasing film thickness. The morphological properties were studied by SEM and showed that films were well adherent to the substrate, uniform, small crystal size and covered the entire substrate surface completely. The optical properties of these films have been studied and show that PbS thin films have the values of energy gap varied between (0.88-1.34 eV) with increasing film thickness.

Synthesis and Characterization of a Semiconductor Diodic Bilayer PbS/CdS Made by the Chemical Bath Deposition Technique

“…Bulk PbS has a cubic crystal structure, high dielectric constant, and high carrier mobility. − A Bohr radius of 18 nm provides a high quantum confinement for electrons and holes, which allows increasing the absorption for solar radiation in the near-IR electromagnetic spectrum. PbS has high absorption within the ultraviolet visible (UV–vis) spectral region and has high transmittance within the IR spectral region, which allow its use in IR detectors. − PbS has extraordinary optical and optoelectronic properties that are principally useful to mention, and some are for IR detection, SCs, photoresistance, diode laser, solar absorbers, quantum dots, transistors, and so on. Its use in the industry has been extensive, and primarily, it was used as a semiconductor in IR detectors due to its ability to absorb the IR spectrum.…”