Vol 5 . Paper 11

Influence of Molar Concentrations on Chemical Bath Deposited Cadmium Sulphide Thin Films

Chioma A. Ejelonu, Peter A. Ilenikhena, Joseph O. Emegha, Tochukwu C. Simon

Keywords: chemical bath deposition, extinction coefficient, optical constants, optoelectronic devices, thin films


Thin films (TFs) of cadmium sulphide (CdS) have been deposited at 300 Kelvin on soda-lime substrates. The effect of the molar concentrations was investigated using the X-ray diffraction (XRD) and UV-Vis Spectrophotometer. The XRD measurements show that the TFs were crystalline and increases with increasing molarities. The optical characteristics of the films were studied at spectra range of 300 – 950 nm. It indicated that the band gap energy ranged between 1.80 to 1.83 eV. The films exhibited high transmittance that increases from 0.2 to 1.0 while the reflectance decreases from 0.2 to 0 as the molar concentration is increased. Other optical constants like extinction coefficient (k), refractive index (n), real (Ɛᵣ) and imaginary (Ɛᵢ) dielectric constants and optical conductivity (σ) were determined with respect to photon energy (eV). These properties of CdS TFs confirm that the material could be beneficial in various optoelectronics applications