Abstract
This Letter reports the localization of optical fields in dielectric nanopillar arrays on a metal film. Large-area arrays of tall (>450 nm) polymer pillars were patterned on an optically thick gold film by solvent-assisted nanoscale embossing. This hybrid dielectric-metal system supports two high-quality band-edge modes, with the mode at the wavelength closest to the array spacing concentrating electromagnetic field intensity at the tops of and extending beyond the nanopillars. Organic dye molecules mixed in the polymer matrix of the nanopillars showed enhanced radiative emission rates and narrow-band and unidirectional fluorescence emission. This hybrid platform offers prospects for strong near-field enhancements from low-index dielectric nanostructures.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 2612-2617 |
| Number of pages | 6 |
| Journal | ACS Photonics |
| Volume | 6 |
| Issue number | 11 |
| DOIs | |
| State | Published - Nov 20 2019 |
Funding
This work was supported by the Vannevar Bush Faculty Fellowship from DoD under Grant N00014-17-1-3023. X.A. was partially supported by China Scholarship Council, National Science Foundation of China (61204074), and Natural Science Foundation of Guangdong Province (2018A0303130056). This work used Northwestern University Micro/Nano Fabrication Facility (NUFAB), which is partially supported by Soft and Hybrid Nanotechnology Experimental (SHyNE) Resource (NSF ECCS-1542205), the Materials Research Science and Engineering Center (DMR-1720139), the State of Illinois, and Northwestern University. This work made use of the EPIC, Keck II, and SPID facility of Northwestern University’s NUANCE Center, which has received support from the Soft and Hybrid Nanotechnology Experimental (SHyNE) Resource (NSF ECCS-1542205); the MRSEC program (NSF DMR-1720139) at the Materials Research Center; the International Institute for Nanotechnology (IIN); the Keck Foundation; and the State of Illinois, through the IIN. This research was supported in part through the computational resources and staff contributions provided for the Quest high performance computing facility at Northwestern University which is jointly supported by the Office of the Provost, the Office for Research, and Northwestern University Information Technology. X.A. thanks Michael P. Knudson, Ankun Yang, Weijia Wang, and Dongjoon Rhee for technical help, Ahmad K. Fumani for helpful discussion, and Jingtian Hu for thoughtful suggestions on the manuscript.
Keywords
- fluorescence enhancement
- hybrid metal-dielectric nanostructures
- narrow band
- soft nanoscale molding
- surface mode
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Biotechnology
- Atomic and Molecular Physics, and Optics
- Electrical and Electronic Engineering