Structural and Optical Properties of NiO-Doped WO₃ Thin Films Prepared by Pulsed Laser Deposition

Document Type : Original Article

Authors

1 Institute of Technology, Middle Technical University (MTU), Baghdad, 10001, Iraq

2 Remote Sensing Unit, College of Science, University of Baghdad, Baghdad, Iraq

3 Department of Remote Sensing, College of Science, University of Baghdad, Baghdad, 10001, Iraq

4 Department of Medical Physics, College of Science, Al-Farahidi University, Baghdad, 10001, Iraq

Abstract

This study investigates the effect of NiO incorporation on the structural and optical properties of WO₃ thin films deposited on glass substrates using pulsed laser deposition (PLD). The NiO concentration is varied (0.2,0.4 and 0.6 wt.%) while maintaining identical deposition conditions to isolate its intrinsic influence. The X-ray diffraction (XRD) analysis of the films indicates a monoclinic structure, with the shift in peaks suggesting lattice distortion due to higher amount of NiO Fourier transform infrared (FTIR) spectra show that the W–O–W and Ni–O vibrational modes are in agreement with the successful incorporation of NiO in WO₃. Optical measurements show a significant drop in transmittance from 85.59% to 24.39% at 500 nm along with increased absorption in the visible region. The optical band gap diminishes from 3.30 eV to 3.00 eV with increasing NiO concentration, owing to defect-induced localized states and structural changes. The film containing 0.6 wt.% NiO possesses high structural disorder and multiphase characteristics leading to strong band gap narrowing and strong optical absorption. The results indicate that the regulated incorporation of NiO may provide a useful strategy for tuning the structural and optical behaviour of WO₃ thin films.

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© 2026 The Author(s). Progress in Physics of Applied Materials published by Semnan University Press. This is an open access article under the CC-BY 4.0 license. (https://creativecommons.org/licenses/by/4.0/)

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Progress in Physics of Applied Materials
Volume 7, Issue 1
In Progress
May 2026
Pages 1-8

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History

  • Receive Date: 01 February 2026
  • Revise Date: 11 May 2026
  • Accept Date: 13 May 2026

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