High performance organic thin-film gas sensor based on Graphene Oxide/TIPS-pentacene hybrid organic semiconducting layer

Bottom-gated, top-contact organic field effect transistors (OFET) based nitrogen oxide (NO2) gas sensors were fabricated by incorporating a hybrid organic semiconducting (OSC) layer, which consisting of 6, 13-bis(triisopropyl-silylethynyl) pentacene (TIPS-pentacene) and Graphene Oxide (GO). By carefully optimizing the proportion of GO in the OSC layer, a tremendous improvement of sensing performance was obtained when exposed to NO2 analyte. Compared with OFET devices based on pure TIPS-pentacene OSC layer, the sensitivity of OFET sensors with hybrid OSC layer had a tenfold enhancement. By analyzing the semiconducting layer through utilizing X-ray diffraction (XPS) and atomic force microscope (AFM), the enhanced sensing performance was attributed to the absorption of the NO2 gas molecules through a porous OSC layer and a preferable interaction between functional groups on the edge of GO sheets and NO2 gas molecules. The improved sensing performance by the hybrid OSC layer also suggests the possibility of GO for the further application in high performance OFET based gas sensors.