title: Plasmon Modes Induced by Anisotropic Gap Opening in Au@Cu2 O Nanorods.
abstract: Integration of semiconductors with noble metals to form heteronanostructures can give rise to many interesting plasmonic and electronic properties. A number of such heteronanostructures have been demonstrated comprising noble metals and n-type semiconductors, such as TiO2 , ZnO, SnO2 , Fe3 O4 , and CuO. In contrast, reports on heteronanostructures made of noble metals and p-type semiconductors are scarce. Cu2 O is an unintentional p-type semiconductor with unique properties. Here, the uniform coating of Cu2 O on two types of Au nanorods and systematic studies of the plasmonic properties of the resultant core-shell heteronanostructures are reported. One type of Au nanorods is prepared by seed-mediated growth, and the other is obtained by oxidation of the as-prepared Au nanorods. The (Au nanorod)@Cu2 O nanostructures produced from the as-prepared nanorods exhibit two transverse plasmon peaks, whereas those derived from the oxidized nanorods display only one transverse plasmon peak. Through electrodynamic simulations the additional transverse plasmon peak is found to originate from a discontinuous gap formed at the side of the as-prepared nanorods. The existence of the gap is verified and its formation mechanism is unraveled with additional experiments. The results will be useful for designing metal-semiconductor heteronanostructures with desired plasmonic properties and therefore also for exploring plasmon-enhanced applications in photocatalysis, solar-energy harvesting, and biotechnologies.
authors.affiliation: College of Chemistry and Molecular Engineering, Zhengzhou University, Zhengzhou, 450001, Henan Province, P. R. China.|Department of Physics, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, P. R. China.|Institute of Nanostructured Functional Materials, Huanghe Science and Technology College, Zhengzhou, 450006, Henan Province, P. R. China.
authors.forename: Shouren
authors.initials: S
authors.lastname: Zhang
authors.affiliation: Department of Physics, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, P. R. China.
authors.forename: Ruibin
authors.initials: R
authors.lastname: Jiang
authors.affiliation: Institute of Nanostructured Functional Materials, Huanghe Science and Technology College, Zhengzhou, 450006, Henan Province, P. R. China.
authors.forename: Yanzhen
authors.initials: Y
authors.lastname: Guo
authors.affiliation: Institute of Nanostructured Functional Materials, Huanghe Science and Technology College, Zhengzhou, 450006, Henan Province, P. R. China.
authors.forename: Baocheng
authors.initials: B
authors.lastname: Yang
authors.affiliation: College of Chemistry and Molecular Engineering, Zhengzhou University, Zhengzhou, 450001, Henan Province, P. R. China.
authors.forename: Xiao-Lan
authors.initials: XL
authors.lastname: Chen
authors.affiliation: Department of Physics, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, P. R. China.
authors.forename: Jianfang
authors.initials: J
authors.lastname: Wang
authors.affiliation: College of Chemistry and Molecular Engineering, Zhengzhou University, Zhengzhou, 450001, Henan Province, P. R. China.|College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, Fujian Province, P. R. China.
authors.forename: Yufen
authors.initials: Y
authors.lastname: Zhao
mesh_terms: D016880:Anisotropy; D006046:Gold / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D049329:Nanostructures / Q000737:chemistry*; D043942:Nanotubes / Q000737:chemistry*; D020349:Surface Plasmon Resonance
chemical_list: D006046:Gold
keywords: core-shell nanostructures; gold; heteronanostructures; nanorods; plasmon resonance