Semiconductor metal oxide gas sensors: A review

• Published in: Materials science & engineering. B, Solid-state materials for advanced technology Vol. 229; pp. 206 - 217
• Main Author: Dey, Ananya
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 01.03.2018; Elsevier BV
• Subjects: Ammonia; Ammonia sensing; Defects; Detection; Dopant induced variations; Dopants; Electronic structure; Gas sensors; Heterojunctions; Metal oxides; Nanowires; Parameter sensitivity; Selectivity; Semiconductor metal oxide; Sensitivity; Sensors; Solid solutions; Stability; Types of gas sensors; Semiconductor metal oxide; Sensitivity; Stability; Ammonia sensing; Types of gas sensors; Selectivity; Dopant induced variations
• ISSN: 0921-5107; 1873-4944
• DOI: 10.1016/j.mseb.2017.12.036

•Sensitivity, Selectivity and stability of Semiconductor Metal Oxide (SMO) gas sensors are studied.•Properties and gas sensing mechanisms of SMOs are discussed in detail.•Mechanisms of dopant induced variations in SMOs to improve the gas sensing properties are reviewed. This review paper encompasses a detailed study of semiconductor metal oxide (SMO) gas sensors. It provides for a detailed comparison of SMO gas sensors with other gas sensors, especially for ammonia gas sensing. Different parameters which affect the performance (sensitivity, selectivity and stability) of SMO gas sensors are discussed here under. This paper also gives an insight about the dopant or impurity induced variations in the SMO materials used for gas sensing. It is concluded that dopants enhance the properties of SMOs for gas sensing applications by changing their microstructure and morphology, activation energy, electronic structure or band gap of the metal oxides. In some cases, dopants create defects in SMOs by generating oxygen vacancy or by forming solid solutions. These defects enhance the gas sensing properties. Different nanostructures (nanowires, nanotubes, heterojunctions), other than nanopowders have also been studied in this review. At the end, examples of SMOs are given to illustrate the potential use of different SMO materials for gas sensing.