Spin-coated nickel doped cadmium sulfide thin films for third harmonic generation applications

• Published in: Journal of alloys and compounds 2017-03, Vol.696, p.1292-1297
• Main Authors: Chtouki, T., El Kouari, Y., Kulyk, B., Louardi, A., Rmili, A., Erguig, H., Elidrissi, B., Soumahoro, L., Sahraoui, B.
• Format: Article
• Language: English
• Subjects: Absorptivity; Atomic force microscopy; Cadmium; Cadmium sulfide; CdS thin film; Chemical Sciences; Crystal structure; Doping; Electron spin; Morphological; Ni doped CdS; Nickel; Nickel alloys; Optical properties; Phase transitions; Sol-gel processes; Sol-gel spin-coating; Spectrometry; Structural; Substrates; THG; Thin films
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2016.12.089

In the current study, different percentages of Nickel (0%, 2%, 4% and 6%) doped CdS thin films have been deposited on glass substrates by the sol-gel spin-coating technique. Before performing the nonlinear optical studies, the structural, morphological and optical properties were examined as a function of Ni doping concentration through the XRD, SEM, AFM and UV–vis spectrometry, respectively. According to the XRD patterns, all films are polycrystalline and the incorporation of Ni does not change qualitatively the crystalline phase of CdS. The Ni doping affects the surface morphology of the CdS thin films which is indicated by scanning electron microscopy and atomic force microscopy images. The band gap was determined via the equation related to the absorption coefficient. It's deduced that the optical band-gap values increased from 2.35 eV to 2.41 eV depending on Ni content. Though, the nonlinear optical properties were determined based on the measurements of the third harmonic generation (THG) using the rotational Maker fringe technique. The results showed that the third order nonlinear optical susceptibilities oscillate between 5.40 × 10−21 m2/V2 for CdS:Ni (2%) and 4.98 × 10−21 m2/V2 for CdS:Ni (6%) while the pure CdS one falls inward, with a value of 5.09 × 10−21 m2/V2. •Studying the structural and morphological properties of the CdS thin films in both the pure and Ni doped forms.•Investigating the correlation between the structural, morphological and nonlinear optical properties of the thin films.•Discussing the third order nonlinear optical properties of the undoped and doped CdS, with different nickel concentrations.