MOLECULAR RECTIFICATION IN ORGANIC QUANTUM-WELLS

We present the first direct observation of molecular rectification as a consequence of asymmetric tunnelling processes through molecular qua ntum wells. As molecular systems we fabricated highly insulating sandw ich structures of the form Au/organic layer/Au. The organic layer cons ists of LB-film based heterostructures of an octasubstituted metalloph thalocyanine and a perylene-3,4,9,10-tetracarboxyldiimide derivative. By applying a special thermal evaporation technique to deposit the tap gold electrode, we have overcome the problem of short-circuits that u sually occur in sandwich structures when using ultrathin films.