Nanofiber-Textured Organic Semiconductor Films for Field-Effect Ammonia Sensors

Abstract

Field-effect gas sensors, integrating the gas sensor and amplification transistor, exhibit excellent sensory performance.Here we report organic thin-film transistors (OTFTs) with nanofiber-textured semiconductor films that exhibit superior ammonia response compared to conventional OTFTs with uniform/flat semiconductor films. The introduce of insulating polymer additives (IPAs) facilitates the formation of semiconducting nanofiber during coating. The effects of IPAs, organic semiconductor/IPA blend ratios and solvents on OTFT-based sensory performance are studied. The results show that the use of SU8 as IPA and chloroform as solvent form intertwined semiconductor nanofibers (~50 nm in diameter) at the bottom. The resulting OTFTs exhibit extraordinarily high sensitivities to ammonia, which reach 13676%/ppm (current) and 457%/ppm (turn-on voltage), respectively. Finite element analysis was conducted to simulate the adsorption/desorption processes of gas molecules and the roles of specific surface area on sensory performance.

Intrinsically Stretchable Subthreshold Organic Transistors for Highly Sensitive Low‐Power Skin‐Like Active‐Matrix Temperature Sensors

“…Recently, the rapid development of intrinsically stretchable organic semiconductor materials, especially organic polymers, has encouraged the potential of OTFTs as skin-like sensors. [5][6][7][8] However, conventional OTFTs must overcome their low-temperature sensitivity and electrical instability under strain to be adopted as skin-like temperature sensors. [9][10][11] In addition, their high operating voltage should be lowered to reduce power consumption, given the limited capacity of rechargeable batteries.…”

“…Recently, the rapid development of intrinsically stretchable organic semiconductor materials, especially organic polymers, has encouraged the potential of OTFTs as skin‐like sensors. [ 5–8 ]…”