Bias modulated highly sensitive NO2 gas detection using carbon nanotubes

A NO2 gas sensor of carbon nanotubes (CNT) array was fabricated by a dielectrophoretic method. It is the first report of 50 ppb level detection operating at room temperature without a supplementary assistance of a heating system, vacuum environment, metal decoration, or additional film coating. The as-deposited CNTs on Pt electrodes by dropping of a CNT cropped solution provided good contact formation without post contact treatment. The bias voltage modulation improved the sensor performance by controlling the Schottky barrier potential. It is highly sensitive NO2 detection at room temperature, which may benefit to reduce the fabrication steps and cost as well.