Study of the structural and optical properties of thallium gallium disulfide (TlGaS2) thin films grown via thermal evaporation

Isik M., KARATAY A., Ech-Chergui A., HASANLI N.

Physica Scripta, vol.97, no.7, 2022 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 97 Issue: 7
  • Publication Date: 2022
  • Doi Number: 10.1088/1402-4896/ac74f0
  • Journal Name: Physica Scripta
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Aerospace Database, Chemical Abstracts Core, Compendex, INSPEC, zbMATH
  • Keywords: layered semiconductors, 2D materials, thin film, optoelectronics, ABSORPTION
  • Middle East Technical University Affiliated: Yes


© 2022 IOP Publishing Ltd.Thallium gallium disulfide (TlGaS2) belonging to layered structured semiconducting family has been a significant compound due to its outstanding characteristics. Its layered characteristics take attention for two-dimensional (2D) material research area and thus TlGaS2 is known as promising layered compound to develop 2D materials for optoelectronic devices. To the best of our knowledge, the present work is the first one investigating TlGaS2 thin films grown by thermal evaporation method. The current study focused into the structural, morphological, and optical characteristics of thermally evaporated TlGaS2 thin films. X-ray diffraction pattern of the films exhibited one peak around 36.10° which was associated with (−422) plane of the monoclinic crystalline structure. The atomic compositional ratio of Tl:Ga:S was found to be suitable for the chemical formula of TlGaS2. Scanning electron microscopy images showed uniformly and narrowly deposited nanoparticles with sizes varying between 100 and 200 nm. Room temperature transmission measurements were recorded to obtain the bandgap energy of the evaporated thin films. Tauc analyses indicated direct band gap energy of 2.60 eV. Finally, Urbach energy was obtained as 95 meV. The results of the present paper would provide valuable insight to 2D material technology to understand the potential device applications of the TlGaS2.