초록 |
In this study, triarylamine derivatives (TPCAs) were designed to investigate the NO2 detection capability of amorphous organic semiconductors (OSCs). The TPCAs exhibited amorphous characteristics with slightly different molecular packing depending on the number of methoxy group units introduced into an identical conjugated framework. The NO2 detection sensitivity was identified with the formation of TPCA-NO2 complex governed by the degree of charge transfer (CT) between electron donating TPCAs and electron accepting NO2. In addition, using a field-effect transistor (FET)-based gas sensor with a patterned active layer, it was demonstrated that the degree of NO2 diffusion is affected by molecular packing. TPCA3M with three methoxy groups exhibited the highest sensitivity resulted from the high degree of CT, the abundant binding sites of NO2, and easier diffusion of NO2 gas due to the weak intermolecular packing. |