Aligned Growth of Semiconductor Nanowires on Scratched Amorphous Substrates

Aligned growth of planar semiconductor nanowires (NWs) on crystalline substrates has been widely demonstrated during the past two decades and was used for the fabrication of a large variety of devices. However, the dependence on single-crystal substrates is a major obstacle in the way of implementing NW-based applications in today's silicon- and glass-based technologies. Here, the guided growth of semiconductor NWs is demonstrated along nanoscale-depth scratches, created in a nonlithographic process on amorphous oxidized silicon wafers and soda-lime glass. Scratches are created on the substrates in a few seconds using a robust and scalable mechanical polishing process. Growth of planar NWs of different materials (CdS, CdSe, ZnSe, and ZnO) guided by scratches on Si/SiO₂ wafers and glass is demonstrated and studied. Photoluminescence measurements from individual NWs grown along scratches show that the interaction with the substrate preserves the optical properties of the material. Crystallographic analysis indicates that all materials grow as single crystals, and the influence of the scratches on the different materials is discussed in terms of morphology, crystallinity, and crystallographic orientations. This process opens the way to large-scale integration of NWs into functional devices by guided growth for various applications including displays, polarized light sensors, and smart windows.