Developments of compact, energy-efficient thin-film-based multilayered oxygen sensors

This short review is intended to provide an overview of the recent developments in the field of multilayered thin films of solid electrolyte-based electrochemical oxygen sensors. This work reviews the factors that prevent the realization of multilayer-based thin film electrochemical sensors and outlines the methodologies to be adopted to circumvent them. It demonstrates the feasibility of energy-efficient compact sensors as they offer low thermal mass and ease of integration with the thin film heater for operation. Design of a multilayered sensor, deposition of high-quality thin films of various components of electrochemical oxygen sensing device, density of YSZ thin film electrolyte, interdiffusion of components and their impact on electrical property, long-term stability of thin layered device and its operation at lower temperatures of about 623 to 673 K as against 923 K for bulk devices have been addressed.