The development of gas sensor technologies with high sensing performance with low power consumption is one of the most urgent tasks to bring precise gas detection to real life in the Internet of Everything (IoE) era. As the last remaining that has not been mimicked by any electronic devices with overwhelming performance over human sensing receptors among human five senses (touch, sight, hearing, smell, and taste), various efforts on developing electronic nose with gas sensors have been extensively on-going. Although various gas sensor principles have been suggested to mimick and electronically realize human smell senses, the chemoresistive type gas sensors are the most appropriate candidate sensor principle due to their simple operating mechanism, easy fabrication, and small size which are the primary requirements for IoE applications, not to mention their promising gas sensing properties. Still, lacking gas selectivity and relatively high power consumption need to be overcome and various strategies have been suggested for solving the limitations, such as i) forming nanostructures, ii) catalysts decoration, iii) forming heterojunctions, iv) utilizing alternative materials (metal oxides, 2-dimensional (2D) materials, conductive polymers, or organic-inorganic hybrid perovskites), or v) utilizing alternative activation sources other than external heaters. This seminar summarizes various strategies for improving gas selectivity and power consumption of chemoresistive gas sensors based on nanostructured semiconducting materials including metal oxides and transition metal dichalcogenides (TMDs).

 

Keywords: Metal oxide, 2D material, Transition metal disulfide, TMDs, Nanostructure, Heterojunction, Chemoresistive, Gas sensor, Light activation, Room temperature, Selectivity, Power consumption