Strengthening optical enhancement with Ag<inf>x</inf>Au<inf>1</inf><inf>−x</inf> alloy and Ag/Au heteromaterial sub-micro disk arrays
Issued Date
2022-11-01
Resource Type
eISSN
21593930
Scopus ID
2-s2.0-85142169948
Journal Title
Optical Materials Express
Volume
12
Issue
11
Start Page
4238
End Page
4251
Rights Holder(s)
SCOPUS
Bibliographic Citation
Optical Materials Express Vol.12 No.11 (2022) , 4238-4251
Suggested Citation
Sitpathom N., Suwanna S., Pijitrojana W., Infahsaeng Y., Pongophas E., Bavontaweepanya R., Deesuwan T. Strengthening optical enhancement with Ag<inf>x</inf>Au<inf>1</inf><inf>−x</inf> alloy and Ag/Au heteromaterial sub-micro disk arrays. Optical Materials Express Vol.12 No.11 (2022) , 4238-4251. 4251. doi:10.1364/OME.471832 Retrieved from: https://repository.li.mahidol.ac.th/handle/20.500.14594/87138
Title
Strengthening optical enhancement with Ag<inf>x</inf>Au<inf>1</inf><inf>−x</inf> alloy and Ag/Au heteromaterial sub-micro disk arrays
Author's Affiliation
Other Contributor(s)
Abstract
Material modification on plasmonic nanostructures is recognized as one of many approaches to increase optical near-field enhancement and resonance wavelength tuning. In this work, with finite-difference time-domain simulation, we showed that closed-hexagonal sub-micro disk arrays of the AgxAu1−x alloy increase electric-field enhancement in the near-infrared spectra at reduced Ag fraction in the alloy, while the arrays of pure Ag does so in the visible spectra. For the enhancement factor in the near-infrared region, the Au array is dominant around the wavelength of 800 nm, whereas the Ag0.74Au0.24 array is slightly stronger at 820 nm. Furthermore, the local confinement in the near-infrared region (800-900 nm) is strengthened by the heteromaterial array of Ag/Au sub-micro disks with alternating rows, which can boost the electric field enhancement at 1.3 and 3.9 times better than those of the pure Au and Ag arrays, respectively. The Ag, Au and Ag/Au plasmonic hexagonal arrays yield the Purcell factors of 2.42 × 105, 1.17 × 104 and 2.72 × 104, respectively, at wavelengths of 695 nm, 828 nm and 795 nm that would be suitable for spontaneous emission rate enhancement in quantum dots.