Controllable synthesis of large scale, catalyst-free, lateral ZnO nanowires network

Abstract

We report a novel method for large scale catalyst-free zinc oxide nanowires (ZnO NWs) network growth on Si substrate using chemical vapor deposition (CVD). The SiO2 layer of the Si substrate is photoetched to SiO2 square pillar array which works as the growth core of urchin-like ZnO NW lump, and the NWs cross over each other forming an integrated network. This method achieves controlled growth of lateral ZnO NW network and allows the in situ nano device fabrication. Meanwhile, the vapor deposition mechanism is discussed and confirmed by contrast experiments along with different growth conditions, which realizes growth on large size substrate. According to the result of Field Emission Scanning Electron Microscope (FE-SEM), the ZnO NWs are wurtzite hexagonal single-crystalline and the network is intact with massive intersection points.