Growth of semiconductor nanowires on iron-patterned silicon substrates

Recent progress in the synthesis of semiconductor nanowires has made an opportunity of testing quantum confinement effects and developing nanodevices based on these materials. However, isolating and manipulating the free-standing tangled nanowires still remain as challenges. It is of interest to grow nanowires on a substrate in a controlled fashion, so that little or no post-growth manipulation is needed for the purpose of measurement or device uses. In this report, we demonstrate that semiconductor nanowires can be grown on iron-patterned silicon substrates using thermal evaporation method or gas transport reaction. In particular, we find that the nanowires are grown only within the patterned iron squares on the substrates. The selective growth of the nanowires on the substrates presents a possibility to position the nanowires by depositing iron into desired areas on substrates. In this way, it is possible to integrate the nanowires into some useful nanostructures or devices.