Persistent ion beam induced conduction in zinc oxide nanowires

Ion implantation gives access to adjustable doping of semiconductor nanowires. However, in several cases not all of the implanted doping species are in fact contributing to the doping level, even after annealing. Additionally, ion implantation is also known to induce radiation damage that can also affect the electrical properties of the nanowires. As a predictable and reliable doping method is of huge necessity for a further integration of nanowires into technology, interest is directed to a closer investigation of implantation induced effects inside nanostructures. In this work, we report persistently increased conduction in ZnO nanowires irradiated by ion beam with various ion energies and species. This effect is shown to be related to the already known Persistent Photo Conduction (PPC) in ZnO and dubbed Persistent Ion beam induced Conduction (PIC). Both effects show similar excitation efficiency, decay rates and chemical sensitivity. PIC will potentially allow countable (i.e. single dopant) implantation in ZnO nanostructures and other materials showing PPC.