Fabrication of the SnO2 nanorods-Si micropillars tree-like structure for gas sensor application

It is the first time that the SnO₂ nanorods are fabricated on Si micropillars surface to form tree-like structures by the hydrothermal method successfully. And this structure is used to the gas sensor application. During the fabrication process, numerous micropillars are prepared on the Si wafer to overcome the SnO₂ nanorods falling off. The SnO₂ nanorods are prepared on the countless Si micropillars surface via a hydrothermal reaction. The Si micropillars, serving as substrates, can improve the adhesion between the SnO₂ nanorods and Si surface, which is a crucial step in successfully growing SnO₂ nanorods on the Si surface. In this study, the main conditions for synthesizing SnO₂ nanorods are optimized, including the concentration of the raw material, reaction time, reaction temperature, and the morphology of the Si micropillar substrate, and the growth principle of the SnO₂ nanorods are researched. Energy dispersive spectroscopy patterns and X-ray diffraction curves indicate that the SnO₂ nanorods on the Si micropillars exhibit high purity and good crystallinity. The Si wafer with this SnO₂ nanorods-Si micropillar tree-like structures is used for gas sensor application, and the results of the gas sensitivity test show a stable gas sensitivity performance for both alcohol and acetone.