Chemical sensing with ZnO nanowires

Zinc oxide nanowires were configured as n-channel field-effect transistors. These transistors were implemented as chemical sensors for detection of various gases. The ammonia sensing behavior of nanowires was observed to switch from oxidizing to reducing when temperature increased from 300 to 500 K. This effect is attributed to the temperature dependent chemical potential shift. Carbon monoxide was found to increase the nanowire conductance in the presence of oxygen. In addition, nanowire detection sensitivity dependence on the diameter was investigated. © 2005 IEEE