Characterization of amorphous CuS thin films obtained from fast time and low temperature of deposition

This work reports the successful deposition of copper sulphide (CuS) thin films by Chemical Bath Deposition on ITO substrates at 27 °C at short deposition times from 20 until 40 minutes using two complexing agents triethanolamine and ammonia. The studies on the properties of the CuS thin films include: X-ray diffraction that indicated the amorphous structure of the material. The XPS characterization demonstrated that Cu and S atoms are presented in the amorphous films. The optical band gap values were in the range from 2.22 to 2.32 eV. The influences of annealing process on the structural, optical and electrical properties also were studied. The surface roughness of annealed samples showed smother surface as compared to their as-deposited. The electrical conductivity changed five orders or magnitude from 10 (Ωcm)^-1 as-deposited to 5.0x10⁶ (Ωcm)^-1 for annealed samples at 150°C. The route presented in this work allows deposit CuS thin films for short deposition times at room temperature. The characteristics obtained in the these films make them suitable candidates for device applications that require low temperature of processing and also low cost, like flexible electronics.