CdS/CdSe quantum-dot sensitized solar cells (QDSCs) were fabricated from ZnO nanorods deposited on fluorine-doped tin oxide (FTO) substrates via the application of polysulfide redox reactions and a CuS counter electrode. In the present study, a TiO2 compact layer was used to suppress the recombination process. Typically, a TiO2 compact layer prevents direct contact between the FTO and electrolyte. The TiO2 compact layer with optimal thickness was fabricated by varying the soaking time in a TiCl4 solution. In addition, the morphology and influence of the compact layer on the interface between the FTO/electrolyte were analyzed.