Work function changes in gas sensitive materials: Fundamentals and applications

The paper reviews the main issues concerning the work function changes in gas sensitive materials, giving few representative examples. Starting from an historical perspective, the most relevant field effect gas sensing approaches are presented and discussed in connection with their proven practical or possible applications. The specific features of both, conducting and insulating gas sensing materials, are summarily analysed and compared with the goal of advancing towards a better understanding of the mechanisms responsible for the field effect gas sensing.