Optimization of Gas-Sensing Properties in Poly(triarylamine) Field-Effect Transistors by Device and Interface Engineering

Abstract

In this study, we investigated the gas-sensing mechanism in bottom-gate organic field-effect transistors (OFETs) using poly(triarylamine) (PTAA). A comparison of different device architectures revealed that the top-contact structure exhibited superior gas-sensing performance in terms of field-effect mobility and sensitivity. The thickness of the active layer played a critical role in enhancing these parameters in the top-contact structure. Moreover, the distance and pathway for charge carriers to reach the active channel were found to significantly influence the gas response. Additionally, the surface treatment of the SiO2 dielectric with hydrophobic self-assembled mono-layers led to further improvement in the performance of the OFETs and gas sensors by effectively passivating the silanol groups. Under optimal conditions, our PTAA-based gas sensors achieved an exceptionally high response (>200%/ppm) towards NO2. These findings highlight the importance of device and interface engineering for optimizing gas-sensing properties in amorphous polymer semiconductors, offering valuable insights for the design of advanced gas sensors.

Biosensors for Odor Detection: A Review

“…In order to extend the detection range, detect harmful gases, objectively evaluate the gas type and intensity, and realize automatic measurement, plenty of gas sensors have been developed. Gas sensors can be divided into different categories according to their transducers such as field-effect transistor (FET) [18][19][20], quartz crystal microbalance (QCM) [21,22], surface acoustic wave (SAW) [23,24], surface plasmon resonance (SPR) [25,26], light-addressable potentiometric sensor (LAPS) [27], microelectrode array (MEA) [28,29], and fluorescence [30,31]. The sensing materials, e.g., carbon nanotube, polymer, carbon black composite, conducting polymer, lipid, or ionic liquid are utilized for odorant measurements.…”