CHARACTERIZATION OF CuxS THIN FILMS OBTAINED BY CBD TECHNIQUE AT DIFFERENTS ANNEALING TEMPERATURES

Copper sulfide thin films were grown on glass substrates at 40 degrees C by the chemical bath deposition technique and post treated in air, nitrogen and vacuum atmospheres during 40 minutes at different temperatures. The [Cu]/[S] concentrations ratios were varied in order to change the thiourea concentration in the range of 1 to 3.0 in steps of 0.5. The thin films obtained were annealed varying the temperature of treatment from 75 to 300 degrees C. Three copper sulfide phases were observed, which depend on the annealing atmosphere and temperature. A conductivity of 7.26x10(-4) Omega-cm is achieved at 200 degrees C in a vacuum atmosphere. The band gap varied from 1.8 to 2.4 eV. The transmittances of the films were in the 50 to 90 % range. X-ray and SEM analysis showed that all the films were nanocrsytalline.