The electrodeposited Cu2O thin films, with a controlled morphology, were obtained by varying the deposition parameters, such as the solution temperature, applied current and charge. An optimal deposition condition was achieved for a better quality Cu2O film which was favorable as an absorber layer for thin-film solar cell application. The effect of applied negative charge on the as-deposited Cu2O films was investigated, resulting in an increase in film thickness with increasing applied charge. The performance of the Cu2O/ZnO heterojunction solar cells with different Cu2O absorber thickness exhibited the highest power- conversion efficiency of 0.52%. Thicker Cu2O was beneficial for the decreased shunt conductance, but it also led to the increased series resistance. The optimal thickness of Cu2O absorber was similar to 3.3 mu m.