We demonstrate a simple and cost-effective synthesis of an organic (polyaniline, PANI)/inorganic (zinc oxide, ZnO) one-dimensional coaxial nanowire (1D-CNW) array directly on a conducting substrate by (1) electrochemical deposition of aniline and its polymerization to PANI on the pore walls of a track-etched polycarbonate membrane and (2) subsequent electrodeposition of ZnO in the core of hollow PANI nanowires (NWs). The surface morphology and heterojunction formation in 1D-CNWs at the interface of PANI (shell)/ZnO (core) are analyzed by field-emission scanning electron microscopy and transmission electron microscopy (TEM). The diameter and length of 1D-CNWs are in the ranges of 50-200 nm and 3-5 mu m, respectively. In addition, the single-crystalline nature of ZnO (inorganic core)/polycrystalline PANI (organic shell) and atomic composition of the inorganic/organic heterojunction are determined by selected-area electron diffraction and TEM-energy-dispersive X-ray spectroscopy, respectively. Amperometric analysis is used to explain the growth mechanism for formation of the core and shell in 1D-CNWs. Photoluminescence (PL) is found to be significantly larger by a factor similar to 3 in the case of PANI/ZnO 1D-CNWs compared to that of ZnO NWs. A model for PANI (shell)/ZnO (core) coaxial 1D-CNWs is also proposed based on heterojunction arrangement to explain the PL enhancement by generation of hole and electron pairs together with minimization of recombination losses upon UV illumination. Subsequently, it also explains the progression of conduction of a free electron all the way through to the polymeric sequence of PANI to get an amplified photocurrent to engender PL enhancement in the visible region.