title: Amplification of hot electron flow by the surface plasmon effect on metal-insulator-metal nanodiodes.
abstract: Au-TiO2-Ti nanodiodes with a metal-insulator-metal structure were used to probe hot electron flows generated upon photon absorption. Hot electrons, generated when light is absorbed in the Au electrode of the nanodiode, can travel across the TiO2, leading to a photocurrent. Here, we demonstrate amplification of the hot electron flow by (1) localized surface plasmon resonance on plasmonic nanostructures fabricated by annealing the Au-TiO2-Ti nanodiodes, and (2) reducing the thickness of the TiO2. We show a correlation between changes in the morphology of the Au electrodes caused by annealing and amplification of the photocurrent. Based on the exponential dependence of the photocurrent on TiO2 thickness, the transport mechanism for the hot electrons across the nanodiodes is proposed.
authors.affiliation: Center for Nanomaterials and Chemical Reactions, Institute for Basic Science, Daejeon 305-701, Korea. Graduate School of EEWS, Korea Advanced Institute of Science and Technology (KAIST) Daejeon 305-701, Korea.
authors.forename: Changhwan
authors.initials: C
authors.lastname: Lee
authors.forename: Ievgen I
authors.initials: II
authors.lastname: Nedrygailov
authors.forename: Young Keun
authors.initials: YK
authors.lastname: Lee
authors.forename: Changui
authors.initials: C
authors.lastname: Ahn
authors.forename: Hyosun
authors.initials: H
authors.lastname: Lee
authors.forename: Seokwoo
authors.initials: S
authors.lastname: Jeon
authors.forename: Jeong Young
authors.initials: JY
authors.lastname: Park