Thin films of ZnO nanoparticulate films have been prepared and modified with CdS quantum dots via chemical bath deposition technique. Photoinduced absorption spectroscopy (PIA), where the excitation is provided by a square-wave modulated (on/off) monochromatic diode light source, is a multipurpose tool in the study of dye-sensitized solar cells. Here, we use PIA as a tool for the study of a quantum-dot modified metal oxide nanostructrued electrode. Oxidized quantum dots can easily be obtained from the spectra of transient species, and their kinetics can be explored using time-resolved techniques. ZnO based CdS photoelectrode has demonstrated best performances in both photoelectrical response and broadening response into visible with a maximum IPCE of 87% at 400 nm. Time constant for electron injection or hole transfer was relatively fast (44 s) and proves at least a well pore filling of ZnO film by ultra fine CdS particles.