Recently, there has been growing interest in the design of novel nano- and/or microscaled heterojunctions consisting of two distinctive ordered semiconductor arrays for highly efficient p-n diodes used in optical, optielectronic, and microelectronic devices. Here, we report the attainment of an ordered double array comprising of p-type polyaniline microrods and n-type ZnO nanowires by a controlled electrochemical deposition method. Extensive chemical and physical characterizations have been performed on the fabricated p-n heterojunction. The double-array p-n heterojunction exhibits good rectifying characteristics, the rectification ratio of which exhibits a minimum at an illumination density of 93 mW cm(-2), making it suitable for high-sensitivity photodetectors. This research is expected to open up a new avenue for the development of highly efficient and sensitive p-n heterojunction diodes and possibly serve as the building blocks for future nanoelectronics.