Effect of complexing agent on growth process and properties of nanostructured Bi2S3 thin films deposited by chemical bath deposition method

Nanostructured Bi2S3 thin films have been prepared onto amorphous glass substrates by chemical bath deposition method at room temperature using bismuth nitrate and sodium thiosulphate as cationic and anionic precursors with EDTA as complexing agent in aqueous medium. The X-ray diffraction study reveals that the films deposited without the complexing agent are amorphous in nature and becomes nanocrystalline in the presence of EDTA. The resistivity for the films prepared from EDTA complexed bath is decreased due to the improvement in grain structure. The decrease in optical bandgap and activation energy is observed as the thickness of the film varies from 45 to 211 nm on account of the variation of the volume of complexing agent in reaction bath. Studies reveal that the growth mechanism of Bi2S3 gets affected in the presence of complexing agent EDTA and shows impact on structural, electrical and optical properties.