Research On Fabrication Of CNTs Ionization Gas Sensor

The field-induced gas discharge process can be electrically characterized by the transition of gases from an insulator to a conductor. The current in the test loop increases from the magnitude of environment noise to a relatively large (>nA scale) and repeatable signal at a certain voltage. The transition completes in a transient time (magnitude of nanoseconds). Theoretically, the transition can be characterized by threshold voltages and/or currents, which were determined by three factors: (1) the geometry and the materials of the electrodes; (2) the species and the concentration of the gases; (3) the method of electrical operation. Therefore, under the condition that the factors of (1) and (3) are given, different gases would produce specific threshold voltages and currents, which reflect the species and the concentration of the gases. The operation of such gas sensors are characterized by fast response time, high sensitivity, and short recover time. However, the risky high operation voltage and the bulky architecture significantly limit its development and application.In order to obtain the high electric field at a relatively low operation...