The Influence of Silicon Nanopillars Structure as the Substrate on the SnO2‐Based Gas Sensor

Abstract

AbstractTin dioxide (SnO2) film is fabricated on the Silicon (Si) nanopillars surface with more than 5 aspect ratio via direct current (DC) magnetron sputtering for the first time. Form the XRD curves, SnO2 film become multi‐crystalline after annealing at 750 °C with 2 hours, and the nanopillars substrates have no influence on the crystallization of the SnO2 film. For the morphology, the SnO2 film on the polished Si surface becomes from planar to plicated after annealing, while there is no morphology change of the SnO2 film on Si nanopillars surface, which proves that the Si nanopillars surface is more suitable for heat and stress release during the annealing process. After testing the gas sensor properties of the SnO2 based gas sensors, the results reveal that the nanopillars based gas sensors have the higher gas response than the planar ones no matter for ethanol or acetone, with or without Au decoration. The Si nanopillars substrate with high aspect ratio makes the SnO2 film to have a larger surface to contact with air and target gas, and to have more defects to react with O2 and reducing gas molecules, which may be a promise method to fabricate the gas sensor with high response.