Co-activation effect of chlorine on the physical properties of CdS thin films prepared by CBD technique for photovoltaic applications

A simple chemical bath deposition (CBD) technique with ultrasonication has been developed and successfully used to deposit cadmium sulfide (CdS) thin films onto glass substrates from a bath containing cadmium salt and thiourea. The structural and electrical properties of the CdS films were investigated. From the X-ray diffraction pattern, the CdS films were found in both hexagonal and cubic phases. Electrical resistivity, carrier concentration and carrier mobility of the films have been reported. The electrical resistivity of the as-deposited-annealed films was in the range 106-108 Ω cm and low for chlorine-doped-annealed films (10-2-102 Ω cm). From the Hall measurements, the films showed n-type conductivity. All the results are presented and discussed. The results of the obtained films are promising to find application in optoelectronic devices as well as window material in heterojunction solar cell fabrication. (copyright 2005 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)