LAUSR

Abstract Spin coating and successive ionic layer adsorption and reaction (SILAR) method were adopted to deposit commercial TiO2 (Degussa-P25), un-dopedCdS and Co2+-doped CdS quantum dots (QDs). Characteristic peak for CdS, TiO2and FTO were observed in powder X-ray diffraction pattern of the prepared samples. Co2+-doping was confirmed through energy dispersive X-ray spectroscopy and elemental mapping analysis. Spherical shaped morphology was observed in field emission scanning electron microscopy (FE-SEM). Measured size of CdS is ~8 nm and the TiO2 is ~20 nm through HR-TEM imaging. The maximum absorption range was observed as 570 nm for 3% Co2+-doped CdS QDs. Power conversion efficiency of un-doped CdS and 3% Co2+-doped CdS QDs were 0.54% and 1.21% respectively. It indicated that up to 3% Co2+-doping in CdS QDs leads to remarkable enhancement in the optical absorption, absorption range and photovoltaic performance under chosen experimental conditions.