Influence of ZnO Nanorods Morphology on the Photovoltaic Properties of ZnO/Cu2O Heterostructural Solar Cells

ZnO nanorods were prepared by electrochemical deposition (ECD). The influence of ECD parameters on the morphologies of ZnO nanorods was studied and optical properties of the ZnO nanorods were measured with optical absorption and specular reflection spectra. It is found that deposition time has significant influence on the length and diameter of ZnO nanorods which is also proved by the optical measurements. ZnO/Cu2O heterostructural solar cells were constructed by ECD with n-type ZnO nanowires and p-type Cu2O films and their photovoltaic characteristics such as open-circuit voltage, short-circuit current density and efficiency were measured. With the increase of nanorods’ length, the photovoltaic properties of ZnO/Cu2O solar cells are enhanced. Finally, the relation between the solar cell performance and the morphologies of ZnO nanorods are discussed. It is indicates that, by increasing the length of nanorods, the light scattering is enhanced, which improves the electronic collection efficiency and photon utilization rate, and accordingly, the performance of solar cells.