Band bending modified tunneling at metal/conjugated polymer interfaces

Metal/polymer interfaces play an important role in polymeric light-emitting diodes. Recent transport measurement studies by Parker promote a rigid band model with triangular barrier tunneling at the metal/polymer interface. This finding, however, stands in contradiction to the band bending and Schottky barrier formation observed using surface analytical techniques. We found that this apparent contradiction can be nicely reconciled if a modification of the tunneling model by band bending is included in the interpretation of the transport data. Band bending modified tunneling gives a clear physical picture of the tunneling process across the metal/polymer interface and is important for low field tunneling processes.