Cadmium sulphide-sensitized zirconium dioxide (ZrO₂) photoanode by successive ionic layer adsorption and reaction for solar cell application

In the present study, cadmium sulphide (CdS) quantum dot-sensitized ZrO₂ photoanodes have been analysed by using the facial and cost-effective method, popularly known as successive ionic layer adsorption and reaction (SILAR), performed at 300 K. The presence of compact layer and ZnS treatment of the as-prepared photoanode is studied in this article to improve the solar cell parameters. The X-ray diffraction peaks infer the nano-crystalline nature of ZrO₂ films with an average particle size of 39.14 nm. The CdS-sensitized ZrO₂ films show a significant increase in absorption of photons in the visible region (i.e., 200 to 520 nm) of the absorption spectrum, as we have increased the number of SILAR cycles. Poly-sulphide electrolytes have been prepared in double distilled water and carbon black soot on conducting substrate is used as a counter electrode to be economical. The J–V characteristic of 10 CdS/ZrO₂ with a compact layer of TiO₂ with surface passivation (ZnS) treatment gives the maximum J_sc of 1.46 mA/cm² with a fill factor of 0.34 and conversion efficiency of 0.46%. Electrochemical impedance spectroscopy of the quantum dot-sensitized solar cell is studied to understand the kinetics of charge transfer and transport processes mechanisms involved.