Growth and characterization of chromium selenide thin films for optoelectronic applications

• Published in: Optical and quantum electronics 2023-12, Vol.55 (14), Article 1254
• Main Authors: Aljaloud, Amjad Salamah M., Qasrawi, A. F., Alfhaid, Latifah Hamad Khalid
• Format: Article
• Language: English
• Subjects: Characterization and Evaluation of Materials; Computer Communication Networks; Deposition; Electrical Engineering; Energy bands; Energy distribution; Energy gap; Lasers; Optical Devices; Optics; Optoelectronics; Permittivity; Photonics; Physics; Physics and Astronomy; Spectra; Terahertz frequencies; Thin films
• ISSN: 0306-8919; 1572-817X
• DOI: 10.1007/s11082-023-05572-4

Herein amorphous and stoichiometric CrSe 2 thin films are obtained by the thermal deposition (TD) technique under a vacuum pressure of 10 −5 mbar. The films are structurally, morphologically, optically and dielectrically characterized. It is observed that CrSe 2 thin films grown by TD technique exhibit optical excitations within direct and indirect allowed energy band gaps of 2.60 eV and 3.19 eV, respectively. The amorphous CrSe 2 thin films contained a wide range of exponential band distribution presented by Urbach energy width of 2.24 eV. In addition in contrast to the chemical bath deposition technique which produced Cr 7 Se 8 films of low dielectric constant ( ε r ∼ 2 ), the TD technique revealed high dielectric constant values up to ε r = 11.9 for CrSe 2 films. Moreover, the Drude-Lorentz modeling of the imaginary part of the dielectric constant spectra revealed drift mobility values in the range of 0.70–6.45 cm 2 /Vs. The plasmon frequency varied in the range of 5.42–8.33 GHz. Furthermore, analysis of the terahertz cutoff frequency ( f co ) spectra have shown that CrSe 2 thin films exhibit f co values in the range of 3.30–40.0 THz. The features of CrSe 2 thin films deposited by the thermal evaporation technique are promising semiconductor layers suitable for 6G and terahertz technology applications.