A new high temperature solid-state microelectronic carbon monoxide gas sensor

Abstract

A new solid-state microelectronic based carbon monoxide (CO) gas sensor, catalytic-SnO/sub x//i-diamond/p/sup +/-diamond/p/sup +/ CAIS diode, has been developed. The CO gas sensing performance and detection mechanism of the new sensor have been studied by using I-V and I-t characteristics as a function of gas concentration over a wide temperature range (50-500/spl deg/C). The gas sensitivity of the sensor is high, repeatable, and reproducible. The response time is in seconds to a small concentration of CO gas. Gas detection mechanism of the new sensor is attributed to the modification of the oxygen vacancies in the SnO/sub x/ layer through the reduction reaction between pre-adsorbed oxygen and CO gases. This new diamond-based microelectronic gas sensor could be applied for the detection of oxidizing and reducing gases over a higher and wider temperature range than currently possible.