Structural, morphological and temperature-tuned bandgap characteristics of CuS nano-flake thin films


Isik M., Terlemezoglu M., HASANLI N., PARLAK M.

Physica E: Low-Dimensional Systems and Nanostructures, vol.144, 2022 (Peer-Reviewed Journal) identifier

  • Publication Type: Article / Article
  • Volume: 144
  • Publication Date: 2022
  • Doi Number: 10.1016/j.physe.2022.115407
  • Journal Name: Physica E: Low-Dimensional Systems and Nanostructures
  • Journal Indexes: Science Citation Index Expanded, Scopus, Academic Search Premier, PASCAL, Applied Science & Technology Source, Compendex, Computer & Applied Sciences, INSPEC
  • Keywords: Copper sulfide, Nanoflake, Optical properties, Optoelectronic applications

Abstract

© 2022 Elsevier B.V.Copper sulfide (CuS) thin films were produced by radio-frequency (RF) magnetron sputtering method. Structural, morphological and optical characteristics of deposited CuS films were presented. X-ray diffraction pattern showed two intensive peaks associated with hexagonal crystalline structure. Scanning electron microscopy image indicated that CuS films have nano-flake structured. Raman spectrum was reported to show vibrational characteristics of the CuS nano-flake thin films. Two peaks associated with Cu–S and S–S vibrations were observed in the Raman spectrum. Transmission spectra were recorded at various temperatures between 10 and 300 K. The analyses accomplished considering Tauc expression demonstrated that direct bandgap energy decreases from 2.36 eV (at 10 K) to 2.22 eV (at 300 K). Temperature-bandgap dependency was analyzed considering Varshni and Bose-Einstein expressions to reveal bandgap at 0 K, rate of change of bandgap and Debye temperature. CuS nanoflake thin film may be used in optoelectronic and photocatalysis applications thanks to its direct and narrow bandgap energy characteristics.