An approach for fabrication of junctions with Langmuir-Blodgett films incorporated between molecular electrodes

Langmuir-Blodgett (LB) assemblies composed of monolayers of different compounds alternating in a predetermined sequence are potential candidates for development in the field of nanoelectronics. However, their poor mechanical stability restricts the possibility of fabrication of interconnected electronic elements because LB films can be easily destroyed during the deposition of metal electrodes. In this work, we present a technique for the fabrication of junctions for the electrical characterization of one-component LB films and LB assemblies enclosed between thin molecular electrodes. The molecular electrodes are produced using LB films of a charge-transfer salt. Such an application of these films became possible due to considerable improvements in their conductivity, quality of deposition and stability in comparison with the properties of films of similar compositions studied previously. Lateral patterning of electrodes is carried out by the it-radiation of conductive films with an electron beam, which results in the loss of their conductivity. In this way, it is possible to prepare the samples for electrical investigations without any damage to incorporated LB films. The LB films of barium stearate. polycyanoacrylate, mixture of surfactant donor and acceptor, porphyrins. as well as the LB assemblies composed of thin layers of these compounds deposited in various sequences were enclosed between the molecular electrodes and studied. Probable conduction mechanisms are discussed on the basis of obtained data.