Hydrogen sulphide detection in extreme environments

The present paper reports a novel approach to detect hydrogen sulphide (H2S) at high temperatures, using a silicon carbide based MIS capacitor. The leakage current is monitored through the gas sensor and is shown to be described by a trap assisted conduction mechanism. The hydrogen-like response of the sensor when exposed to H2S is observed by lowering the barrier height between the palladium metal gate and the insulator of the device. Reliable low electric field current-voltage characteristics are obtained at 325 0C and ultimate sensitivities below 50 ppm are reported. The suitability of this technology for the remote monitoring of volcanic emissions is outlined and predictions made for the deployment in other applications, including outer space