Toward molecular modulation of electronic devices

COLL 405

David Cahen, david.cahen@weizmann.ac.il, materials & interfaces, Weizmann Institute of Science, Herzl street, Rehovoth, 76100, Israel
We explore two main ways to use molecules in molecular electronics, electrostatically, as dipolar films and electrodynamically, where current passes through them. For the former we find that incomplete partial dipolar molecular films can control diode behaviour and that this effect extends to poly- and nano-crystalline solar cells. For the latter complete monolayers are needed, as ideal as possible to assure current transport through the molecules. Such systems with alkyl chain monolayers behave like ideal MIS diodes with significant photovoltaic activity, due to the remarkable insulating behavior of the monolayer. Recently we started to combine the two effects by adding dipolar character to the completely covering alkyl monolayers, enabling modulating the electronic quality of the monolayers. Chemically the interesting aspect is that the introduction of strong leaving groups on the monolayers allows nucleophilic substitutions, to allow further reactions. This, thus, creates a platform for further molecular device modification.