Abstract:
A method for the preparation of CdS thin films on glass substrate by chemical bath deposition was developed. The films prepared at 65 , 75 and 80 ℃ have a smooth surface with sheet resistance of about 1011 Ω/▭, and an energy gap of about 2.47 2.60 eV. Optical transmittance is about 80% for photon energy less than energy gap. The sheet resistance of the films can be lowered by doping with chlorine in doping solution of 0.01 molar HgCl2by immersing the films into solution for 10 minutes followed by annealing in N2 atmosphere or in air for 20 minutes at 200 ℃. It was found that the sheet resistance can be reduced to the value of 105 - 106 Ω/▭ while the energy gap decreases to be about 2.36-2.57 eV as annealing temperature increases. The preparation of CdS Films by chemical bath deposition technique was used to prepare CdS films layer of thin film ZnO(Al)/CdS/CuInSe2/Mo solar cells with cells efficiency of 2.5% which have been measured under 844 W/m2 illumination at the Semiconductor Physics Research Laboratary (SPRL).