Modified chemical deposition and physico-chemical properties of copper sulphide (Cu2S) thin films

Semiconducting stoichiometric copper sulphide (Cu2S) thin films were deposited using modified chemical deposition method. The preparative conditions such as concentration, pH of cationic and anionic precursors, adsorption, reaction and rinsing time durations, complextant, etc. were optimized to get stoichiometric Cu2S thin films. The structural, surface morphological, compositional, optical and electrical characterization were carried out with the help of X-ray diffraction (XRD), scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM), Rutherford back scattering (RBS), optical absorbance/transmittance, electrical resistivity and thermoemf studies. The films were found to be nanocrystalline. Absorbance of the film was high (104 cm-1) with optical band gap of 2.35 eV. The electrical resistivity was of the order of 10-2 Ω cm with p-type electrical conductivity