title: Surface plasmon-driven hot electron flow probed with metal-semiconductor nanodiodes.
abstract: A continuous flow of hot electrons that are not at thermal equilibrium with the surrounding metal atoms is generated by the absorption of photons. Here we show that hot electron flow generated on a gold thin film by photon absorption (or internal photoemission) is amplified by localized surface plasmon resonance. This was achieved by direct measurement of photocurrent on a chemically modified gold thin film of metal-semiconductor (TiO(2)) Schottky diodes. The short-circuit photocurrent obtained with low-energy photons is consistent with Fowler's law, confirming the presence of hot electron flows. The morphology of the metal thin film was modified to a connected gold island structure after heating such that it exhibits surface plasmon. Photocurrent and optical measurements on the connected island structures revealed the presence of a localized surface plasmon at 550 ± 20 nm. The results indicate an intrinsic correlation between the hot electron flow generated by internal photoemission and localized surface plasmon resonance.
authors.affiliation: Graduate School of EEWS (WCU) and NanoCentury KI, KAIST, Daejeon, Republic of Korea.
authors.forename: Young Keun
authors.initials: YK
authors.lastname: Lee
authors.forename: Chan Ho
authors.initials: CH
authors.lastname: Jung
authors.forename: Jonghyurk
authors.initials: J
authors.lastname: Park
authors.forename: Hyungtak
authors.initials: H
authors.lastname: Seo
authors.forename: Gabor A
authors.initials: GA
authors.lastname: Somorjai
authors.forename: Jeong Young
authors.initials: JY
authors.lastname: Park