Work-function modification of the (1 1 1) gold surface upon deposition of self-assembled monolayers based on alkanethiol derivatives

Highlights: •We model the electronic properties of SAM/gold interfaces at a theoretical DFT level. •We examine changes in the metal work-function upon SAM deposition. •Modulation of the work-function can be achieved by changing the anchoring groups. •Intermolecular interactions between electroactive substituents can drastically affect the molecular packing. -- Abstract: The modification in the work-function of the (1 1 1) gold surface upon deposition of self-assembled monolayers (SAMs) based on alkanethiol derivatives has been characterized at the Density Functional Theory level when introducing chemical derivatizations. Chemical derivatizations have been introduced by: (i) replacing thiol as anchoring group by selenol or isocyanide functionalities; and (ii) introducing terminal electroactive substituents varying by their electron donor versus acceptor character. Changes in the anchoring group have shown that substitution of S by Se has no significant impact on the total work-function shift. Consideration of various terminal substituents has also pointed to the key role played by internal restructuration of the SAM geometry on the work-function. These results contribute in establishing guidelines toward a fine control of interface engineering in opto-electronic devices