Defect-Free and Annealing Influences in P3HT Organic Field-Effect Transistor Performance

Abstract

Organic field effect transistors were fabricated using photolithography and plasma etching technique with defect free Poly(3-hexylthiophene) (P3HT) and P3HT 90 % regioregular with different temperatures of annealing at normal ambient. PVA (Poly - vinyl Alcohol) was used as gate dielectric and Ni contacts formed the source and drain electrodes. Improvement of transistor stability and increase of carrier mobility with use of defect free P3HT was reached. The stability enhancement permitted an higher ION current during stress. The auto-encapsulation process involved in the process of fabrication permits an ambient stability, in which the transistors do not degrade due to moisture and oxygen. All the transistors operate at low voltages, due to the high dielectric constant of PVA, being adequate to actual applications. P3HT films deposited in the same conditions as in the active area of the transistors were analyzed by photoluminescence and XRR measurements and it was observed an improvement in crystallinity for the defect free P3HT annealed at lower temperatures, which corroborates the results observed in the transistors characteristics.