Charge injection process in organic field-effect transistors

The charge injection process in top-contact organic field-effect transistors was energetically observed with displacement of the Fermi level as a result of scanning the gate voltage. Doping of charge-transfer molecules into the metal/organic interface resulted in low interface resistance, which unveiled the bulk transport of the injected charges from the contact metal into the channel. The authors found that the bulk transport clearly obeys the Meyer-Neldel rule, according to which the exponential density of states near the band edge limits the charge injection.