Long-chain 3,4-ethylenedioxythiophene/thiophene oligomers and semiconducting thin films prepared by their electropolymerization.

A series of soluble H-terminated conjugated oligomers incorporating 3,4-ethylenedioxythiophene (EDOT) combined with a small number of thiophene units and ranging in length from four to eight EDOT/thiophene groups was prepared with the ultimate goal to investigate if facile formation of a reactive trication radical species would enable electrochemical polymerization of such long-chain oligomers. Spectroscopic and electrochemical studies of the oligomers revealed some general dependencies of their electronic properties on the total number and position of EDOT groups. It was the number of consecutive EDOT units rather than total number of these units which was found to have the most profound effect on electronic energy gap and conjugation length.

Semiconducting polymer thin films by surface-confined stepwise click polymerization.

Surface-confined stepwise click polymerization was used to prepare surface-attached thin films of semiconducting polymers. These highly uniform films showed extended UV/vis absorption characteristics and a remarkable degree of molecular organization with a unidirectional alignment of the polymer chains normal to the surface.

Electropolymerizable 2,2'-Carboranyldithiophenes. Structure-Property Investigations of the Corresponding Conducting Polymer Films by Electrochemistry, UV-Visible Spectroscopy and Conducting Probe Atomic Force Microscopy.

Carborane-functionalized conducting polymer films have been electrogenerated in dichloromethane from the anodic oxidation of ortho- (1), meta- (3) and para-carborane (4) isomers linked to two 2-thienyl units. The corresponding electrochemical response was characterized by a broad reversible redox system corresponding to the p-doping/undoping of the polythiophene backbone, the formal potential of which increased in the order poly(1) < poly(3) < poly(4), from ca. 0.

Self-assembled monolayer initiated electropolymerization: a route to thin-film materials with enhanced photovoltaic performance.

Continuing progress in the field of organic polymer photovoltaic (PV) devices requires the development of new materials with better charge-transport efficiency. To improve this parameter, we have investigated surface-attached bilayer polymer PV thin films prepared starting from a covalently attached monolayer of an electroactive initiator using sequential electropolymerization of dithiophene and its derivatives. These systems were found to show significantly increased photocurrent generation quantum yields as compared to systems made through conventional approaches.