IDENTIFICATION OF THE PROCESS PRODUCING OBSERVED RECTIFYING CHARACTERISTICS OF METAL LANGMUIR-BLODGETT-FILM METAL STRUCTURES

We have previously reported rectifier-like characteristics observed in the electrical response of metal/LB film/metal structures. It was difficult to attribute the rectifier-like properties entirely to the molecule incorporated in the LB film and to eliminate the inherent sample asymmetry as the predominant process. In our studies the donor-acceptor molecule was chosen because of its potential rectifier-like behaviour. The donor-acceptor resonance can be selectively suppressed (bleached) whilst spread as a monomolecular Langmuir film on the subphase. Junctions fabricated from bleached films have exhibited radically different I/V traces from the unbleached molecule. The most important difference is the absence of the high conduction in forward bias as observed in the "rectifying" junctions. The results presented support the argument that the rectifier-like conduction is molecular in origin.