Bottom-Up Electrochemical Fabrication of Conjugated Ultrathin Layers with Tailored Switchable Properties

Verena Stockhausen (1) , van Quyen Nguyen (1, 2) , Pascal G.P. Martin (1) , Jean Christophe Lacroix (1)

1 ITODYS (UMR_7086) - Interfaces, Traitements, Organisation et Dynamique des Systèmes
2 USTH - University of Science and Technology of Hanoi

A bottom-up electrochemical process for fabricating conjugated ultrathin layers with tailored switchable properties is developed. Ultrathin layers of covalently grafted oligo(bisthienylbenzene) (oligo(BTB)) are used as switchable organic electrodes, and 3,4-ethylenedioxythiophene (EDOT) is oxidized on this layer. Adding only a few (less than 3) nanometers of EDOT moieties (5 to 6 units) completely changes the switching properties of the layer without changing the surface concentration of the electroactive species. A range of new materials with tunable interfacial properties is created. They consist of oligo(BTB)-oligo(EDOT) diblock oligomers of various relative lengths covalently grafted onto the underlying electrode. These films retain reversible redox on/off switching and their switching potential can be finely tuned between +0.6 and −0.3 V/SCE while the overall thickness remains below 11 nm.

Keywords: molecular electronics; nanoelectrochemistry; ultrathin film; π-conjugated material; diazonium grafting; bottom-up approach

Domains: Chemical Sciences; Theoretical and/or physical chemistry

Verena Stockhausen, van Quyen Nguyen, Pascal G.P. Martin, Jean Christophe Lacroix. Bottom-Up Electrochemical Fabrication of Conjugated Ultrathin Layers with Tailored Switchable Properties. ACS Applied Materials & Interfaces, 2017, 9 (1), pp.610-617. ⟨10.1021/acsami.6b08754⟩. ⟨hal-01821774⟩