Enhancement of plasmon-induced charge separation efficiency by coupling silver nanocubes with a thin gold film

Abstract

"Enhancement of plasmon-induced charge separation efficiency by coupling silver nanocubes with a thin gold film," J. Photon. Energy 6(4), 042505 (2016), doi: 10.1117/1.JPE.6.042505. Abstract. Plasmon-induced charge separation (PICS), in which an energetic electron is injected from a plasmonic nanoparticle (NP) to a semiconductor on contact, is often inhibited by a protecting agent adsorbed on the NP. We addressed this issue for an Ag nanocube-TiO 2 system by coating it with a thin Au layer or by inserting the Au layer between the nanocubes (NCs) and TiO 2 . Both of the electrodes exhibit much higher photocurrents due to PICS than the electrodes without the Au film or the Ag NCs. These photocurrent enhancements can be explained in terms of PICS with accelerated electron transfer, in which electron injection from the Ag NCs or Ag@Au core-shell NCs to TiO 2 is promoted by the Au film, or PICS enhanced by a nanoantenna effect, in which the electron injection from the Au film to TiO 2 is enhanced by optical near field generated by the Ag NC.