The fabrication and optimization of OTFT formaldehyde sensors based on Poly(3-hexythiophene)/ZnO composite films

Formaldehyde (HCHO), a colorless and pungent-smelling gas, is confirmed be a huge threat to human health. The detection of formaldehyde is necessary and important. The Poly(3-hexythiophene) (P3HT)/ZnO organic-inorganic composite thin film was fabricated and used as the sensitive layer of organic thin film transistors (OTFT) by spray-deposited method to detect HCHO at room temperature. The process parameters such as P3HT/ZnO weight ratios and airbrushed masses were optimized. The results showed that P3HT/ZnO OTFT exhibited good sensing response to HCHO. Airbrushed mass of 1ml was the optimal mass, and the 1:1 and 1:5 weight ratios of P3HT/ZnO exhibited better sensing properties compared with others. OTFT gas sensors based on P3HT/ZnO composite film provides a novel promising approach to the detection of HCHO.