Graphene-induced enhancement of charge carrier mobility and air stability in organic polythiophene field effect transistors

Abstract

We investigate multifunctional graphene nanostructures as charge carrier mobility enablers and moisture and air barrier films for organic-based polythiophene field effect transistors. Primary results show that a tiny amount of graphene flakes blended in the polythiophene active channel could reach a ten-fold increase in effective transistor mobility. Moreover, densely packed honeycomb graphene for efficient moisture and air shielding is firstly applied on organic active channels without any supporting polymer, resulting in mild mobility degradation in ambient environment with respect to unprotected polythiophene devices. Thus, hybrid graphene-polythiophene blend transistors laminated with graphene passivation layers exhibit significantly superior and prolonged performances over 1400 h, whereas the hybrid devices without graphene passivation become unswitchable in 600 h. Moreover, their low processing temperature (< 150 degrees C), solution processability, and flexibility of both graphene and polythiophene makes them a highly promising means for next-generation organic field effect transistors.