Growth and characterization of p-Cu₂O/n-ZnO nanorod heterojunctions prepared by a two-step potentiostatic method

p-Cu₂O/n-ZnO nanorod heterojunctions were fabricated by a two-step process. The process was performed with potentiostatic deposition of n-ZnO nanorods on conductive indium-tin-oxide (ITO) glasses followed by potentiostatic deposition of p-Cu₂O to form p-Cu₂O/n-ZnO nanorod heterojunctions. The deposition condition required to form the cuprous oxide layer affected significantly the formation and microstructure of the p-Cu₂O/n-ZnO nanorod heterojunctions. In particular, the high-quality p-Cu₂O/n-ZnO nanorod heterojunctions were obtained only at relatively high temperatures of 90 and 100 C. The p-Cu₂O/n-ZnO nanorod heterojunctions exhibited a well-defined p-n diode characteristic with an ideality factor of about 4.3.