Compensation of disorder for extraordinary optical transmission effect in nanopore arrays fabricated by nanosphere photolithography

Abstract

The work considers the effect of extraordinary optical transmission (EOT) in polycrystalline arrays of nanopores fabricated via nanosphere photolithography (NPL). The use of samples with different qualities of polycrystalline structure allows us to reveal the role of disorder for EOT. We propose a phenomenological model which takes the disorder into account in numerical simulations and validate it using experimental data. Due to the NPL flexibility for the structure geometry control, we demonstrate the possiblity to partially compensate the disorder influence on EOT by the nanopore depth adjustments. The proposed experimental and theoretical results are promising to reveal the NPL limits for EOT-based devices and stimulate systematic studies of disorder compensation designs.

A versatile technology for colloidal crystal transfer using parylene coatings and hydrosoluble polymers

“…In this section we demonstrate that resonant plasmonic excitations are possible in metallized nanopore arrays, prepared via NPL and colloidal transfer, despite the disordered polycrystalline nature of samples. These results are consistent with our previous theoretical and experimental studies [26,34].…”

“…for the hexagonal lattice [36,26]; ε d and ε m are dielectric permittivities of dielectric and metallic layers, respectively, and σ 0 is the interpore distance defined by the diameter of the self-assembled particles. Taking ε d ≈ 1.6 2 for the S1805 dielectric resist, ε m ≈ (0.16+5.3i) 2 for gold and σ 0 = 580 nm, we estimate the EOT wavelength λ EOT ≈ 840 nm defined by 6 symmetrical first diffraction orders (m, n) = (±1, 0), (0, ±1), (±1, ∓1).…”

“…The same remark applies to the work [24] as well, where the sacrificial polymethylmethacrylate (PMMA) thin film was degraded under 254 nm UV irradiation for 30 min. It should be noted that intensive UV irradiation during the transfer process is incompatible with perspective Nanosphere Photolithography (NPL) method of surface nanostructuration [25,26], where photonic nanojets are used for resist exposure. NPL-fabricated metasurfaces are used in active photonics [27], surface texturing [28], plasmonic sensors [29] etc.…”

“…On the other hand, this approach is difficult to implement into device fabrication with sensitive functional films demanding to the environmental conditions like photoresists and photocatalytic surfaces, because it utilizes tough steps like heating at 100 °C for 3 h and PVA calcination at 550 °C for 5 h. The same remark applies to the work [25] as well, where the sacrificial polymethylmethacrylate (PMMA) thin film was degraded under 254 nm UV irradiation for 30 min. It should be noted that intensive UV irradiation during the transfer process is incompatible with perspective Nanosphere Photolithography (NPL) method of surface nanostructuration [26,27], where photonic nanojets are used for resist exposure. NPL-fabricated metasurfaces are used in active photonics [28], surface texturing [29], plasmonic sensors [30] etc.…”

Effects of metallic underlayer on SERS performance of a metal film over nanosphere metasurface

“…The EOT transmission band of the MFON structure is quite broad, with an FWHM of 100-200 nm depending on the disorder of the hexagonal monolayer of the close-packed PS beads. Moreover, this band appears on the longer-wavelength wing of the reflection spectrum, satisfying the PSP excitation mechanism of the EOT phenomenon [20,37].…”