Zinc oxide (ZnO) has a band gap energy of 3.3 eV, which is similar to that of TiO₂ used as a n-type semiconductor in solar cells, and has higher electron mobility than TiO₂. Thus, ZnO film can act as the n-type semiconductor in solar cells. However, ZnO-based solar cells suffer from low power conversion efficiency, because Zn²⁺/dye complex is formed during prolonged sensitization process. The complex could hinder electron injection from excited dye to ZnO. In this study, electrophoretic technique was applied to increase dye-loading amount in a short sensitization time. The dye-loading amount by electrophoretic method for 20 min was increased by 2.18x10^-5mol/㎤, compared to that (1.56x10^-5mol/㎤) by conventional soaking process for the same time. This led to an increase in power conversion efficiency of ZnO-based solar cells.