ABSTRACT
1D nanostructure materials have attracted great attention in recent years 1 – 3 as they provide interesting possibilities for resistance-less transport due to quantum effects. Another remarkable property of such 1D semiconductor materials is their sensitivity to ambient conditions such as humidity, oxygen level, and so on. Their resistance can be modulated by adsorbed gases capable of electron/hole injection/withdrawal from conduction and valence bands. Such an electron transfer creates a carrier depletion layer near the solid–air interface increasing the device impedance. This increase/decrease in resistance provides a convenient response with respect to analyte concentration. Furthermore, the sensor devices can be made more specific for a given type of gas through the use of dopants that selectively interact with the analyte gas. Additionally, doping can further amplify the device sensitivity and its dynamic range by providing an increase in the carrier concentration.
