ORGANIC QUANTUM-WELLS - MOLECULAR RECTIFICATION AND SINGLE-ELECTRON TUNNELING

We present the first direct observation of molecular rectification as a consequence of asymmetric tunneling process through molecular quantu m wells. In addition, single-electron tunnelling effects were observed which might be attributed to the charging of single molecules or mole cular stacks. As molecular systems we used LB-film-based heterostructu res consisting of an octasubstituted metallophthalocyanine and a peryl ene-3,4,9,10-tetracarboxyldiimide derivative sandwiched between two go ld electrodes. By using a special thermal evaporation technique to dep osit the top gold electrode, we have overcome the problem of short cir cuits and were able to fabricate highly reproducible devices.