In this communication, I will present studies combining plasmonic nanostructure and pi-conjugated systems. I will describe active molecular plasmonic devices in which pi conjugated molecules and polymers, grafted on gold nanoparticles, are used to tune the plasmonic properties of metal nanostructures. I will also discuss two emerging research fields, i.e. plasmonic electrochemistry and plasmonic molecular electronics. In the first one, electrochemical reactions are controlled and triggered by plasmon which yield to various electrochemical reactions at the nanoscale induced by light. The second one combines molecular plasmonics and molecular electronics in plasmonic molecular devices. These new fields of research use hot carriers generated in plasmonic systems when irradiated at the wavelength of the localized plasmon resonance to trigger electrochemical reaction or charge injection in molecules

I will show that it is possible to control at the local scale plasmon induced reduction of diazonium salt and to graft selectively oligo(bis-thienylbenzene) layers on various nanostructure (1). I will also show that hot electrons generated when gold nanoparticles are irradiated  can be used to switch the conductance of a PEDOT nanojunction in an SECM configuration. (2) and will extend this concept to solid state in solid state large area molecular junction. Such results indicate that Plasmonic electrochemistry and plasmonic molecular electronic may become important research fields

References

1. Plasmon-Induced Nanolocalized Reduction of Diazonium Salts VQ Nguyen, Y Ai, P Martin, JC Lacroix ACS Omega, 2017, 2 (5), 1947-1955.
2. Plasmon-Induced Conductance Switching of an Electroactive Conjugated Polymer Nanojunction. Ai, Y.; Nguyen, V. Q.; Ghilane, J.; Lacaze, P.C.; Lacroix, J.C.  ACS Applied Materials & Interfaces, 2017, 9 (33), 27817-27824