Recent Advances and Trends in Metal Oxide-based Semiconductor Gas Sensors

With rapid industrial development, a large amount of waste gases has been produced, causing severe industrial disasters and human health problems. In order to avoid gas-related accidents and prevent potential health issues, the detection and monitoring of hazardous gases is essential. In order to effectively detect harmful gases, semiconductor gas sensors have gained increasing attention due to their high sensitivity, small size, cost-effectiveness and ease of manufacturing. This article reviews metal oxide-based semiconductor gas sensors. Firstly, features of metal oxide-based semiconductor gas sensors including major advantages and limitations are discussed. Then, the operating mechanism of semiconductor gas sensors are discussed with a list of widely studied metal oxides. Finally, the semiconductor gas sensors made of four different metal oxides – i) tin oxide (SnO2), ii) indium oxide (In2O3), iii) zinc oxide (ZnO), and iv) tungsten trioxide (WO3) – are discussed from the aspects of current challenges, recent research strategies and future perspectives.