Molecular rectification in oriented polymer structures

The intrinsic rectifying nature of an oriented polymeric material sandwiched between symmetrical metal electrodes is underlined. Orientation of the initially symmetric structure is performed through d.c.-field ordering of the polar molecules contained in the polymer. The resulting internal field induced in the polymeric material is evidenced by the induction of a rectifying current-voltage characteristic of the polarized symmetrical structure. Second-harmonic generation and time-of-flight experiments confirm the molecular-diode nature of the individual molecules.