인천대학교 인디고클랫폼 인천대학교 기술지원허브

Creating gas sensors with excellent selectivity and sensitivity is essential for applications in air quality control and workplace hazard detection. In this study, we explored the effects of surface-functionalized silica particles on the performance of organic field-effect transistor (OFET) based gas sensors using poly(3-hexylthiophene) (P3HT) as the active layer. Silica particles were modified with self-assembled monolayers (SAMs), including methyl (C), ethylenediamine (2 N), diethylenetriamine (3 N), and thiol (S) groups as well as the bare hydroxyl (O) group, to enhance gas adsorption. The gas sensing performance was evaluated for nitrogen dioxide (NO₂), sulfur dioxide (SO₂), and carbon dioxide (CO₂). The 3 N-silica demonstrated the highest sensitivity to NO₂ due to strong amine- gas interactions. In contrast, for SO₂, the S-silica exhibited the highest sensing performance due to the strong chemical interaction between SO₂ and the thiol groups. Additionally, air stability tests revealed that function alized silica enhances the long-term stability of OFET devices, with 3 N- and O-silica achieving the highest recovery rates because of the strong adsorption of H₂O. These findings provide a crucial direction for advancing next generation organic electronic devices by addressing the challenges of low sensitivity and stability in organic gas sensors.