Synthesis and optical properties of lead sulfide and copper sulfide thin films deposited by chemical bath deposition method for application in solar cells

We report the synthesis and Optical properties of crystalline Copper sulfide and Lead sulfide thin films were deposited on glass substrate using the chemical bath deposition method [CBD] at room temperature for 22 hour 23 minute and 72 hours respectively. Copper sulfide was synthesized using copper sulphate and thiourea, while Lead nitrate and thiourea were used for the synthesis of lead sulfide thin films. Optical properties of the thin films were studied by spectrophotometer in the wavelength range of 200 nm-800 nm. Band gap [Eg], absorbance [A] and absorption coefficients [α] were examined as a function of wavelength and photon energy. Further analysis revealed that Cu₂S and PbS thin films had a band gap of 2.324 eV and 2.586 eV respectively, suitable for solar cell applications.