Electrical molecular switch addressed by chemical stimuli

Hassib Audi (1) , Yannick Viero (2) , N Alwhaibi (3) , Zhongrui Chen (4) , Maksym Iazykov (4) , Arnaud Heynderickx (4) , Fan Xiao (4) , David Guérin (2, 5) , Christophe Krzeminski (2, 6) , Iain Mark M Grace (3) , Colin J Lambert (3) , Olivier Siri (4) , Dominique Vuillaume (2, 7) , Stéphane Lenfant (2, 7) , H.R. Klein (4, 8)

1 ICMUB - Institut de Chimie Moléculaire de l'Université de Bourgogne [Dijon]
2 IEMN - Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520
3 Lancaster University
4 CINaM - Centre Interdisciplinaire de Nanoscience de Marseille
5 CMNF - IEMN - Centrale de Micro Nano Fabrication - IEMN
6 PHYSIQUE - IEMN - Physique - IEMN
7 NCM - IEMN - Nanostructures, nanoComponents & Molecules - IEMN
8 AMU - Aix Marseille Université

We demonstrate that the conductance switching of benzo-bis(imidazole) molecules upon protonation depends on the lateral functional groups. The protonated H-substituted molecule shows a higher con-ductance than the neutral one (G pro > G neu), while the opposite (G neu > G pro) is observed for a molecule laterally functionalized by amino-phenyl groups. These results are demonstrated at various scale lengths: self-assembled monolayers, tiny nanodot-molecule junctions and single molecules. From ab initio theoretical calculations, we conclude that for the H-substituted molecule, the result G pro > G neu is correctly explained by a reduction of the LUMO-HOMO gap, while for the amino-phenyl functionnalized molecule, the result G neu > G pro is consistent with a shift of the HOMO, which reduces the density of states at the Fermi energy.

Domaines: Physique [physics]

Hassib Audi, Yannick Viero, N Alwhaibi, Zhongrui Chen, Maksym Iazykov, et al.. Electrical molecular switch addressed by chemical stimuli. Nanoscale, 2020, 12 (18), pp.10127-10139. ⟨10.1039/D0NR02461A⟩. ⟨hal-02555592⟩