EN
CdS quantum dots were coated on TiO_2 layer by successive ionic layer adsorption and reaction method. An efficient photovoltaic energy conversion and significant quantum-size effect were observed. The magnitude of the short-circuit photocurrent density J_{SC} was found to be approximately 6.01 mA/cm^2 for graphene oxide-incorporated CdS/TiO_2 solar cell, while the J_{SC} of only CdS-sensitized solar cells was lower than 4.40 mA/cm^2. The efficiency of the CdS/TiO_2 solar cell with a graphene oxide layer containing CdS QDs was 60% higher than that of the CdS/TiO_2 solar cell. The cell efficiency was remarkably improved with the graphene oxide-incorporation. The carrier recombination of the QDs sensitized solar cells based on CdS-coated TiO_2 was significantly suppressed due to photogenerated charge carrier transports resulting from the presence of graphene oxide.