Effects of complexing agent on CdS thin films prepared by chemical bath deposition

CdS films have been prepared by chemical bath deposition (CBD) without stirring using weak and strong complexing agents, i.e., ammonia and ethylenediaminetetraacetic acid (EDTA). The optical, structural, and morphological properties of chemical bath deposited CdS films have been investigated. When the complexing agent is ammonia, five peaks in the X-ray diffraction (XRD) patterns from the CdS film, respectively, correspond to the interplanar spacing of 3.5498, 3.3429, 3.1449, 2.0574, and 1.7487 Angstrom, which are definitely ascribed to hexagonal structure; unfortunately, this hexagonal US film is with poor morphology and its optical property in the visible region is not desirable for the solar cells. While, when the complexing agent is EDTA, three diffraction peaks in the XRD patterns from the CdS film, respectively, correspond to the interplanar spacing of 3.1164, 2.6716, and 1.8507 Angstrom, indicating that the film is of a cubic structure. Furthermore, the CdS film has good morphology and its optical property in the visible region is compliant to the requirements of solar cells. (C) 2003 Elsevier B.V. All rights reserved.