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 65⁰C. 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.

Keywords: CBD, XRD, band gap, PbS thin film

DOI: 10.7176/CMR/12-7-01

Publication date:September 30^th 2020