Large-Scale Sub-1-nm Random Gaps Approaching the Quantum Upper Limit for Quantitative Chemical Sensing
KAUST DepartmentComputer, Electrical and Mathematical Sciences and Engineering (CEMSE) Division
Electrical Engineering Program
Material Science and Engineering
Material Science and Engineering Program
Physical Science and Engineering (PSE) Division
Embargo End Date2021-10-28
Permanent link to this recordhttp://hdl.handle.net/10754/665736
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AbstractMetallic nanostructures with nanogap features can confine electromagnetic fields into extremely small volumes. In particular, as the gap size is scaled down to sub-nanometer regime, the quantum effects for localized field enhancement reveal the ultimate capability for light–matter interaction. Although the enhancement factor approaching the quantum upper limit has been reported, the grand challenge for surface-enhanced vibrational spectroscopic sensing remains in the inherent randomness, preventing uniformly distributed localized fields over large areas. Herein, a strategy to fabricate high-density random metallic nanopatterns with accurately controlled nanogaps, defined by atomic-layer-deposition and self-assembled-monolayer processes, is reported. As the gap size approaches the quantum regime of ≈0.78 nm, its potential for quantitative sensing, based on a record-high uniformity with the relative standard deviation of 4.3% over a large area of 22 mm × 60 mm, is demonstrated. This superior feature paves the way towards more affordable and quantitative sensing using quantum-limit-approaching nanogap structures.
CitationZhang, N., Hu, H., Singer, M., Li, K., Zhou, L., Ooi, B. S., & Gan, Q. (2020). Large-Scale Sub-1-nm Random Gaps Approaching the Quantum Upper Limit for Quantitative Chemical Sensing. Advanced Optical Materials, 2001634. doi:10.1002/adom.202001634
SponsorsThis work was partially supported by NSF CMMI-1562057 and ECCS-1807463. The authors appreciate Dr. Lingmei Liu and Prof. Yu Han at KAUST for helpful suggestions on TEM characterization.
JournalAdvanced Optical Materials