Interfacial issues in the design and the making of solid state chemical sensors

The durability of a device is determined by the stability of its interfaces. The aim of this paper is to compare and to discuss problems connected with interphase stability, as they reflect on chemical-sensor design and operation. Case studies will be considered, concerning issues such as the degradation of the interface between the electrolyte and the auxiliary layer and interface-related degradation in semiconductor sensors. In the former the active mechanism of response degradation is the formation of an interface at the electrolyte-auxiliary layer interface, while in the latter the slow migration of defects throughout the grain dominates. All discussion will be carried out with reference to the relationship between preparation procedures and device structure and chemistry.