Development and Comparison Analysis of OTFT Gas Sensors Based on P3HT-ZnO Composite Film and P3HT/ZnO Bilayer Film

Poly (3-hexylthiophene) (P3HT) and zinc oxide (ZnO) composite and bilayer films were deposited on thin film transistor (TFT) as the sensitive layer by spray deposition method for the nitrogen dioxide (NO2) gas sensor application. The electrical and NO2-sensing properties of sensors were tested and analyzed, and the surface morphology of films was characterized and compared by scanning electron microscope (SEM). The results showed that the P3HT-ZnO composite film TFT sensor exhibited better sensing properties than the P3HT/ZnO sensor, which was explained by both morphology analysis and heterojunction models of films.