The effect of annealing temperature on surface roughness and certain optical characteristics of sol-gel spin-coated Nb2O5 thin films

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Ataşer T., Akın Sönmez N., Asar T., Özçelik S.

Journal of Optoelectronics and Advanced Materials, cilt.24, sa.3-4, ss.151-161, 2022 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 24 Sayı: 3-4
  • Basım Tarihi: 2022
  • Dergi Adı: Journal of Optoelectronics and Advanced Materials
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Compendex
  • Sayfa Sayıları: ss.151-161
  • Anahtar Kelimeler: Nb2O5 thin films, Sol-gel spin-coating, Annealing temperature, Surface roughness, Optical characteristics, PHOTOLUMINESCENCE PROPERTIES, ELECTRICAL-PROPERTIES, FABRICATION, PARAMETERS, POWER
  • Gazi Üniversitesi Adresli: Evet

Özet

© 2022 National Institute of Optoelectronics. All rights reserved.Nb2O5 thin film was coated onto SLG substrate by sol-gel spin-coated technique and sintered at 120 ∘C, and was named as as-deposited film. Then, pieces of the sample were annealed at different temperatures (200-600 ∘C) to investigate the effect of annealing temperature on surface roughness and certain optical characteristics of the films. The structural and morphological properties of the as-deposited and annealed films were investigated by XRD and AFM measurements and were associated with optical results. The optical properties of the films were further examined by using UV-Vis spectra and calculating optical constants and parameters. The annealing temperature affected on absorption coefficient (α), extinction coefficient (k), refractive index (n) and dielectrics (εr, εi) of the films. It was observed that the surface roughness and particle size of the films as well as the optical constants increased with the annealing temperature. In addition, the optical band gap energy (Eg) of the films red-shifted with increasing annealing temperature, while Urbach energy (EU) and electron-phonon interaction (Ee-p) increased. The most important outcome of this work is that annealing temperature can be used to tune the mentioned optical characteristics of the Nb2O5 films. Furthermore, the results obtained indicated that Eg of the films can be increased up to 4.58 eV by controlling disorders in the band gap region for several optical applications.