Structural, Optical and Electrical Properties of p-CuS:Cu+and n-CuS:Sn4+ Films Deposited with a Chemical Bath Deposition

This work presents the manufacturing and potential application of the CuS films in recent literature and patents and then focus on the chemical bath depostion of p-CuS: Cu+and n-CuS: Sn4+ filmsat room temperature by controlling S/Cu molar ratio in the bath solution and doping Cu+ and Sn4+ cations, respectively. The CuS:Cu+and CuS:Sn4+ films with S/Cu molar ratio larger and less than the stoichiometric ratio showed p-type and n-type electrical conduction, respectively, and low electrical resistivity of~1.31×10-3 Ω·cm and ~0.73-0.80×10-3 Ω·cm, respectively. Moreover, the films had the average transmittance of ~20.1-30.1 % in 290-1100 nm. The direct allowed band gaps and indirect allowed optical band gap energies of the films were estimated to be in the ranges of ~2.58-2.63 eV and ~1.6-1.78 eV, respectively. The extinction coefficient, refractive index, dielectric constant, and optical conductivity of the films were calculated with the transmittance and reflectance spectra.