Fast chemical sensing with metal-insulator silicon carbide structures

It is demonstrated that the current-voltage characteristics of platinum-thin insulator silicon carbide diodes react rapidly to changes of the concentration of oxygen and hydrocarbons in the ambient already at temperatures around 500/spl deg/C-600/spl deg/C. In this letter, we use moving gas outlets to, for the first time, estimate time constants of the response in the order of a few milliseconds. The short time constants of these sensors make them suitable for applications in combustion monitoring. The new method to modulate gas concentrations rapidly at surfaces has the potential to be a valuable tool for evaluation of device structures for fast chemical sensing.