TY - JOUR
T1 - Flash Ablation of Tunable and Deep-Subwavelength Nanogap by Using a Spatially Modulated Femtosecond Laser Pulse for Plasmonic Application
AU - Xu, Zhijie
AU - Jiang, Lan
AU - Li, Xiaowei
AU - Wang, Andong
AU - Li, Bohong
AU - Huang, Lingling
AU - Lin, Zemeng
AU - Huang, Ji
AU - Lu, Yongfeng
N1 - Publisher Copyright:
Copyright © 2019 American Chemical Society.
PY - 2019/8/23
Y1 - 2019/8/23
N2 - The fabrication of gold nanostructures on a dielectric substrate with a nanogap between the opposite tips is suitable for the excitation of hot spots. In this study, a novel and efficient one-step method is reported for fabricating a gold bowtie nanogap by using a spatially shaped femtosecond laser pulse. The size of the nanogap could be flexibly controlled by adjusting the pulse energy. The smallest nanogap produced by the proposed method measures 30 nm (≈1/26 of the laser wavelength). The formation mechanism of the different morphologies is investigated. Combined with a phase- and amplitude-based beam-shaping technique, the bridge could be manipulated. Both experimental surface-enhanced Raman scattering spectra and simulated finite-difference time-domain results are used to characterize the plasmonic properties of the fabricated bowtie nanogap. The manufacturing scalability of the proposed method is demonstrated through the fabrication of a matrix of nanostructure, which exhibits great uniformity, achieving a density of 2.13 × 106 devices cm-2. Large-area microgaps can be patterned on a terahertz metasurface through the proposed method. The proposed technique provides a simple, flexible, and efficient alternative method for nanogap fabrication. The method can be extensively implemented in biosensing, photovoltaics, and nanophotonics.
AB - The fabrication of gold nanostructures on a dielectric substrate with a nanogap between the opposite tips is suitable for the excitation of hot spots. In this study, a novel and efficient one-step method is reported for fabricating a gold bowtie nanogap by using a spatially shaped femtosecond laser pulse. The size of the nanogap could be flexibly controlled by adjusting the pulse energy. The smallest nanogap produced by the proposed method measures 30 nm (≈1/26 of the laser wavelength). The formation mechanism of the different morphologies is investigated. Combined with a phase- and amplitude-based beam-shaping technique, the bridge could be manipulated. Both experimental surface-enhanced Raman scattering spectra and simulated finite-difference time-domain results are used to characterize the plasmonic properties of the fabricated bowtie nanogap. The manufacturing scalability of the proposed method is demonstrated through the fabrication of a matrix of nanostructure, which exhibits great uniformity, achieving a density of 2.13 × 106 devices cm-2. Large-area microgaps can be patterned on a terahertz metasurface through the proposed method. The proposed technique provides a simple, flexible, and efficient alternative method for nanogap fabrication. The method can be extensively implemented in biosensing, photovoltaics, and nanophotonics.
KW - bowtie nanogap
KW - femtosecond laser ablation
KW - plasmonic application
KW - scalable fabrication
KW - spatial light modulation
UR - http://www.scopus.com/inward/record.url?scp=85078554458&partnerID=8YFLogxK
U2 - 10.1021/acsanm.9b00894
DO - 10.1021/acsanm.9b00894
M3 - Article
AN - SCOPUS:85078554458
SN - 2574-0970
VL - 2
SP - 4933
EP - 4941
JO - ACS Applied Nano Materials
JF - ACS Applied Nano Materials
IS - 8
ER -