Vacuum-processed polyethylene as a dielectric for low operating voltage organic field effect transistors

► Vacuum-evaporated polyethylene (PE) is a highly stable and trap-free dielectric. ► PE supports low-hysteresis transport in C60 and pentacene. ► PE additionally allows ambipolar transistor operation of 6,6′-dibromoindigo with balanced mobilities of ∼0.3 cm2/Vs. ► This work shows that high-quality gate dielectrics consisting of polymeric materials can be vacuum-processed.