SYNTHESIS AND APPLICATION OF NATURAL DYE SENSITIZD CdS THIN FILMS AS PHOTOANODE FOR DSSC

Natural dyes obtained from plants, vegetables and fruits are widely studied and tested as low cost sensitizer for dye sensitized solar cell ( DSSC) in order to replace the rare and expensive inorganic and organic sensitizers. Although, many works have been done using TiO2, ZrO2, ZnO etc. as the nanoporous semiconductor, little importance was given to the use of CdS thin film as a cost effective alternative. In the present study CdS thin films were synthesized by chemical bath deposition (CBD) technique and its optical, structural and morphological properties were investigated by XRD, SEM and UV-Vis absorption spectroscopy. The as synthesized films were found to be nanoporous in nature and are favorable for adsorbing the dyes on to its surface. Two natural dyes extracted from locally available plant leaves namely lawsonia inermis linn and caesalpinia pulcherrima were then adsorbed on the as synthesized CdS thin films for the formation of the working electrode for application in DSSC. The interaction between the nanoporous CdS thin films and the natural dyes were investigated through UV-Vis absorption spectroscopy with an aim to fabricate working electrode for application in DSSC.