High sensitive NO2 gas sensor with low power consumption using selectively grown ZnO nanorods.

The noble gas sensor using multiple ZnO nanorods was fabricated with CMOS compatible process and sol-gel growth method on selective area and gas response characteristics to NO2 gas of the sensor device were investigated. We confirmed the sensors had high sensitive response denoted by the sensitivity of several tens for NO2 gas sensing and also showed pretty low power consumption close to 20 mW even though the recovery of resistance come up to almost the initial value.

Gas-phase production of gold-decorated silica nanoparticles.

Gold-decorated silica nanoparticles were synthesized in a two-step process in which silica nanoparticles were produced by chemical vapor synthesis using tetraethylorthosilicate (TEOS) and subsequently decorated using two different gas-phase evaporative techniques. Both evaporative processes resulted in gold decoration of the silica particles. This study compares the mechanisms of particle decoration for a production method in which the gas and particles remain cool to a method in which the entire aerosol is heated. Results of transmission electron microscopy and visible spectroscopy studies indicate that both methods produce particles with similar morphologies and nearly identical absorption spectra, with peak absorption at 500-550 nm. A study of the thermal stability of the particles using heated-TEM indicates that the gold decoration on the particle surface remains stable at temperatures below 900 °C, above which the gold decoration begins to both evaporate and coalesce.