Effect of Metal Doped Zinc Oxide Nanorods on Photoelectrical Characteristics of ZnO/Polyaniline Heterojunction

The n-type vertically aligned metal doped ZnO nanorods (NRs) and p-type proton acid doped polyaniline (PANI) inorganic/organic heterojunction diodes have been fabricated. Aluminium (Al) and iron (Fe) doped ZnO NRs were grown on seed ZnO layer on fluorine doped tin oxide coated glass substrates by high temperature chemical bath deposition method. The elemental analysis using EDAX confirm doping of Al and Fe in ZnO. The morphology of doped ZnO nanorods and ZnO/PANI heterojunction exhibit well defined uniform nanorod arrays and interface between nanorods and polyaniline matrix respectively. The dark current–voltage curves confirmed the rectifying diode like behaviors of the heterojunctions, whereas under illumination, the junction revealed good sensitivity to UV and visible range with increased current densities. The highest ideality factor and lowest barrier height was found for FeZnO/PANI heterojunction under dark and under light compared to that of ZnO/PANI, AlZnO/PANI. This research is innovative with respect to low cost synthesis of efficient and sensitive hybrid p–n junction diodes and possibly serves as the building blocks for future optoelectronic applications.