SnO2: The most important base material for semiconducting metal oxide-based materials

Abstract As the Internet of things (IoT) becomes a reality, sensors will become indispensable. In order to be widely used, sensors must be small, inexpensive, sensitive, and robust. Semiconducting metal oxide-based (SMOX) gas sensors fulfill these requirements and, today, they are already used for a broad spectrum of applications. Of all the semiconducting metal oxides, SnO2 is the most commonly used base material for SMOX-based sensors. This chapter will briefly introduce the reader to SMOX-based sensors. The relationship between the semiconductor properties and the sensing characteristics will be examined. How the surface chemistry results in an electric signal will be detailed. A historical overview will explain the success of SnO2 as an exemplary SMOX for certain applications. The use of technology to optimize and adjust the sensing qualities (size, response, stability, etc.) of SnO2 for different applications will be described. Finally, the current and possible future applications of SnO2 will be reviewed. The authors predict that the importance of SnO2-based sensors will increase in the future. This chapter offers readers a solid basis from which to understand the working principal, tuning possibilities, and application opportunities of SnO2-based sensors.