α-sexithiophene based organic thin film transistors as gas sensor

A bottom contact organic thin-film transistor (OTFT) using a-sexithiophene (α-6T) as an active layer was fabricated in this paper. α-6T was deposited via vacuum evaporation onto a SiO
2
/n-Si substrate and was characterized by scanning electron microscope (SEM). The current-voltage characteristics of the α-6T OTFT and its response to different concentrations of methanol, alcohol and secondary butyl alcohol vapor were investigated. It was found that the drain-source current in the saturation region decreases rapidly when the OTFT was exposed to methanol, alcohol and secondary butyl alcohol vapor. The results showed that such α-6T OTFT sensors are promising to act as a novel class of chemical sensors.