Band gap determination of chemically deposited Cu2S/Fe2O3 quaternary thin films

Abstract

Quaternary thin films of Cu2S/Fe2O3 have been synthesized via simple, inexpensive and highly reproducible chemical bath deposition technique. The grown films were characterized with Rutherford backscattering technique (RBS), X-ray diffractometer (XRD), scanning electron microscope (SEM), and spectrophotometer for compositional, structural, morphological, and optical properties respectively. The multiple peaks exhibited by the various XRD patterns of the films showed that the films are polycrystalline while the SEM analysis showed an increase in grain size and uniformity of grain distribution as temperature increases. The absorbance (A), transmittance (T), absorption coefficient (  ), band gap (  g ), extinction coefficient (k), real ( r  ) and imaginary dielectric ( i  ) constants were modified by thermal annealing. The optical and solid state analysis for Cu2S/Fe2O3 thin films indicate that A ≤ 0.66, T ≤ 92 %,  ≤ 1.70 x 106m -1 ,  g increases from 3.75-3.85 eV, k ≤ 3.75, r  ≤ 8.5 and i  ≤ 2.05. The high transmittance in the infrared region of Cu2S-Fe2O3 thin films deposited suggest that the films can be used as coating materials for the construction of poultry houses in order to protect young chicks which have not developed protective thick feather from UV radiation while admitting the heating portion of electromagnetic spectrum into the house for warming young chicks. Based on the wide band gap exhibited by all the quaternary thin films, they are promising materials for window layers in solar cell fabrication and fabrication of optoelectronic devices, etc.