title: Bimetallic structure fabricated by laser interference lithography for tuning surface plasmon resonance.
abstract: Tuning of surface plasmon resonance by gold and silver bimetallic thin film and bimetallic dot array is investigated. Laser interference lithography is applied to fabricate the nanostructures. A bimetallic dot structure is obtained by a lift-off procedure after gold and silver thin film deposition by an electron beam evaporator. Surface plasmon behaviors of these films and nanostructures are studied using UV-Vis spectroscopy. It is observed that for gold thin film on quartz substrate, the optical spectral peak is blue shifted when a silver thin film is coated over it. Compared to the plasmon band in single metal gold dot array, the bimetallic nanodot array shows a similar blue shift in its spectral peak. These shifts are both attributed to the interaction between gold and silver atoms. Electromagnetic interaction between gold and silver nanostructures is discussed using a simplified spring model.
authors.affiliation: Department of Electrical and Computer Engineering, 4 Engineering Drive 3, Singapore 117576.
authors.forename: C H
authors.initials: CH
authors.lastname: Liu
authors.forename: M H
authors.initials: MH
authors.lastname: Hong
authors.forename: H W
authors.initials: HW
authors.lastname: Cheung
authors.forename: F
authors.initials: F
authors.lastname: Zhang
authors.forename: Z Q
authors.initials: ZQ
authors.lastname: Huang
authors.forename: L S
authors.initials: LS
authors.lastname: Tan
authors.forename: T S A
authors.initials: TS
authors.lastname: Hor
mesh_terms: D004574:Electromagnetic Fields; D004867:Equipment Design; D006046:Gold / Q000737:chemistry; D007834:Lasers; D053768:Metal Nanoparticles / Q000737:chemistry; D008670:Metals / Q000737:chemistry; D049329:Nanostructures / Q000737:chemistry; D055095:Optics and Photonics; D012834:Silver / Q000737:chemistry; D013053:Spectrophotometry / Q000379:methods; D013056:Spectrophotometry, Ultraviolet / Q000379:methods; D020349:Surface Plasmon Resonance / Q000295:instrumentation* / Q000379:methods*; D014466:Ultraviolet Rays
chemical_list: D008670:Metals; D012834:Silver; D006046:Gold