Investigation of a model molecular-electronic rectifier with an evaporated Ti–metal top contact

Abstract

Molecular-electronic devices are usually fabricated by sandwiching organic monolayers between electrodes. Questions arise about whether the molecules react with a deposited metal. We investigated a self-assembled monolayer (SAM) of alkoxynaphthalene thiol (I) on Pt before and after Ti film deposition. The SAM on Pt was highly ordered. Ti deposition resulted in some reaction with the alkyl chains and disordering, but the napthelenes remained intact. Pinhole free films of the monolayers were characterized by current–voltage measurements, revealing that a rectification ratio as high as 5×105 was achieved.