title: Self-assembly nanoparticle based tripetaloid structure arrays as surface-enhanced Raman scattering substrates.
abstract: This paper reports a novel highly ordered tripetaloid structure array (TPSA) which performs very well as an active surface-enhanced Raman scattering (SERS) substrate. The TPSA is easily fabricated by anisotropic etching of a self-assembly silica-nanoparticle bilayer and a subsequent metal deposition step, with notable uniformity and reproducibility. Electromagnetic simulation indicates that the narrow inter-gaps and edge protrusions in the TPSA act as hot spots. In addition, the peak electromagnetic field intensity in the inter-gaps changes slightly and periodically as the polarization of the incident light varies from 0° to 360°. SERS experiments show that the SERS enhancement factor (EF) of a Au-film-covered TPSA is 12 times higher than that of regular Au-film-over-nanoparticles, and not sensitive to the polarization of the incident light. The spatially averaged EF of the TPSA is as high as 5.7 × 10(6), and the local EF of its hot spots is much higher.
authors.affiliation: National Key Laboratory of Science and Technology on Micro/Nano Fabrication, Institute of Microelectronics, Peking University, Beijing 100871, People’s Republic of China.
authors.forename: Mingrui
authors.initials: M
authors.lastname: Sun
authors.forename: Chuang
authors.initials: C
authors.lastname: Qian
authors.forename: Wengang
authors.initials: W
authors.lastname: Wu
authors.forename: Wenxuan
authors.initials: W
authors.lastname: Yu
authors.forename: Yifei
authors.initials: Y
authors.lastname: Wang
authors.forename: Haiyang
authors.initials: H
authors.lastname: Mao
mesh_terms: D003460:Crystallization / Q000379:methods*; D008027:Light; D008422:Materials Testing; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D010316:Particle Size; D012542:Scattering, Radiation; D020349:Surface Plasmon Resonance / Q000379:methods*