Poly (3, 3‴-dialkylquaterthiophene) Based Flexible Nitrogen Dioxide Gas Sensor

A poly (3, 3"'-dialkylquaterthiophene) (PQT-12) based flexible metal-semiconductor-metal nitrogen dioxide (NO
₂
) gas sensor fabricated on a flexible polyamide substrate has been reported in this article for the first time. The thin PQT-12 film deposited on the polyamide substrate is investigated by X-ray diffraction, atomic force microscopy, and scanning electron microscopy. The sensor shows a gas response of ~24% with a response time of ~41 s at a very low concentration of 100-ppb NO
₂
gas under ambient air atmosphere. The gas response of -48% is measured at higher concentration of 500-ppb NO
₂
gas. The NO
₂
gas detection has been illustrated using a prototype circuit for the proposed sensor.