Oxide p-n Heterojunction of Cu_2O/ZnO Nanowires and Their Photovoltaic Performance

摘要

Oxide p-n heterojunction devices consisting of p-Cu_2O-ZnO nanowires were fabricated on ITO/glass substrates and their photovoltaic performances were investigated.The vertically arrayed ZnO nanowires were grown by metal organic chemical vapor deposition, which was followed by the electrodeposition of the p-type Cu_2O layer. Prior to the fabrication of solar cells, the effect of bath pH on properties of the absorber layers was studied to determine the optimal condition of the Cu_2O electrodeposition process. With the constant pH 11 solution, the Cu_2O layer preferred the (111) orientation, which gave low electrical resistivity and high optical absorption.The Cu_2O (pH 11)/ZnO nanowire-based solar cell exhibited a higher conversion efficiency of 0.27% than the planar structure solar cell (0.13%), because of the effective charge collection in the long wavelength region and because of the enhanced junction area.