Air-Stable Operation of Organic Field-Effect Transistors on Plastic Films Using Organic/Metallic Hybrid Passivation Layers

We investigated the stability of organic field-effect transistors (FETs) under ambient conditions. By employing organic/metallic hybrid passivation layers, we improved the electric stability of organic FETs in air. Pentacene FETs were fabricated on plastic films and encapsulated in organic/metallic hybrid passivation layers. These FETs exhibited a high mobility of 0.6 cm 2 V -1 s -1 and an on/off ratio greater than 10 6 . When the devices were stored in air for two months, the change in mobility was less than 2%. When continuous source–drain and gate voltages of -40 V were applied to the FETs for 10 days in air, the change in saturation current was less than 5%. We performed bending and heating tests in air. The FETs retained their functionality after being bent with a bending radius of less than 1 mm, and exhibited no changes in the performance after being subjected to a number of heat cycles up to 160 °C. The organic/metallic hybrid passivation layer is also effective in reducing air degradation of n-type organic FETs.