Nanostructured CdS thin films doped with Cu were synthesized by chemical bath deposition. The structural, morphological, optical and opto-electronic properties of CdS were modified by Cu doping and resulted in the formation of nanostructured films. No compounds other than CdS were formed in this process. The atomic force microscopy (AFM) studies showed that the particle morphology transformed from spherical to nanostructured or amorphous for un-doped to doped, caused by Cu doping. The optical absorption maxima was displaced for the doped films compared to the un-doped films, so also variation in the band gap energy (Eg) which may be attributed to the variation in the grain size of the films with doping. The intensity of photocurrent response of the doped CdS was reduced compared to the un-doped films, due to the increase in the minority carrier concentration by Cu doping.
CdS:Cu, nanostructure, chemical doping, photocurrent, p-type semiconductor
The authors acknowledge the technical assistance received from Gildardo Casarubias and Maria Luisa Ramon in the characterization of the materials. The financial support for the project was received from DGAPA-UNAM through the project IN113107.
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