The development of low-power room-temperature gas sensors with high sensitivity and stability remains a critical challenge in organic electronics. Conventional metal-oxide sensors operate at elevated temperatures and suffer from high power consumption, while polymer-based organic field-effect transistor (OFET) sensors often face poor stability and limited molecular organization. In this study, ordering and aggregation in poly 2,5-bis(3-tetradecylthiophen-2-yl) thieno[3,2-b thiophene] PBTTT are achieved by incorporating two-dimensional (2D) reduced graphene oxide (rGO) nanosheets decorated with gold nanoparticles(AuNPs) in the polymer environment. At the air/liquid interface, thin films of the PBTTT/Au-rGO composite are formed by a rapid floating-film transfer technique. The incorporation of Au-decorated rGO into PBTTT enhances structural ordering, as evidenced by grazing-incidence X-ray diffraction (GI-XRD) analysis. The composite film shows an increased lamellar coherence length compared with pristine PBTTT, confirming improved molecular organization. Ultraviolet–visible (UV–vis) analysis of the composite reveals a reduced bandgap and a broadened Urbach tail, indicating local disorder yet improved conjugation. Furthermore, the fabricated organic field-effect transistors (OFETs) exhibited an average mobility of 0.33 cm2/V·s in the saturation region at VDS = −40 V and VGS = −40 V, which is about 6 times that of pristine polymer (μ = 0.05 cm2/V·s). The OFET operated with microampere drain currents, demonstrating energy-efficient operation compared with that of heated metal-oxide sensors. The fabricated device has been thoroughly investigated for ammonia gas sensing and has shown a high sensing response of 86% for 14 ppm at VGS = −40 V and VDS = −40 V. Our research has identified a route for the rapid growth of molecularly assembled, high-grade functional thin films for improving gas-sensing response.
Nikhil et al. (Thu,) studied this question.