Structural and optical properties of thermally evaporated Cu-Ga-S (CGS) thin films


Gullu H. H., IŞIK M., Gasanly N.

PHYSICA B-CONDENSED MATTER, cilt.547, ss.92-96, 2018 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 547
  • Basım Tarihi: 2018
  • Doi Numarası: 10.1016/j.physb.2018.08.015
  • Dergi Adı: PHYSICA B-CONDENSED MATTER
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.92-96
  • Anahtar Kelimeler: Thin films, Ternary semiconductor, Optical properties, VI SEMICONDUCTOR NANOCRYSTALS, CU3GA5S9 SINGLE-CRYSTALS, ELECTRICAL-CONDUCTIVITY, ABSORPTION, DIFFUSION, CUGAS2
  • Orta Doğu Teknik Üniversitesi Adresli: Evet

Özet

The structural and optical properties of thermally evaporated Cu-Ga-S (CGS) thin films were investigated by Xray diffraction (XRD), energy dispersive X-ray spectroscopy (EDS), atomic force microscopy (AFM) and optical transmittance measurements. The effect of annealing temperature on the results of applied techniques was also studied in the present paper. EDS results revealed that each of the elements, Cu, Ga and S are presented in the films and Cu and Ga concentration increases whereas S concentration decreases within the films as annealing temperature is increased. XRD pattern exhibited four diffraction peaks which are well-matched with those of tetragonal CuGaS2 compound. AFM images were recorded to get knowledge about the surface morphology and roughness of deposited thin films. Transmittance measurements were applied in the wavelength region of 300-1000 nm. Analyses of the absorption coefficient derived from transmittance data resulted in presence of three distinct transition regions in each thin films with direct transition type. Crystal-field and spin-orbit splitting energies existing due to valence band splitting were also calculated using quasicubic model.