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Optical nano-woodpiles: large-area metallic photonic crystals and metamaterials.

Ibbotson LA, Demetriadou A, Croxall S, Hess O, Baumberg JJ - Sci Rep (2015)

Bottom Line: Previous routes use electron-beam lithography or direct laser writing but widespread application is restricted by their expense and low throughput.Control of stacking sequence, asymmetry, and orientation elicits great control, with visible-wavelength band-gap reflections exceeding 60%, and with strong induced chirality.Such flexible and stretchable architectures can produce metamaterials with refractive index near zero, and are easily tuned across the IR and visible ranges.

View Article: PubMed Central - PubMed

Affiliation: NanoPhotonics Centre, Cavendish Laboratory, Department of Physics, JJ Thompson Ave, University of Cambridge, Cambridge, CB3 0HE, UK.

ABSTRACT
Metallic woodpile photonic crystals and metamaterials operating across the visible spectrum are extremely difficult to construct over large areas, because of the intricate three-dimensional nanostructures and sub-50 nm features demanded. Previous routes use electron-beam lithography or direct laser writing but widespread application is restricted by their expense and low throughput. Scalable approaches including soft lithography, colloidal self-assembly, and interference holography, produce structures limited in feature size, material durability, or geometry. By multiply stacking gold nanowire flexible gratings, we demonstrate a scalable high-fidelity approach for fabricating flexible metallic woodpile photonic crystals, with features down to 10 nm produced in bulk and at low cost. Control of stacking sequence, asymmetry, and orientation elicits great control, with visible-wavelength band-gap reflections exceeding 60%, and with strong induced chirality. Such flexible and stretchable architectures can produce metamaterials with refractive index near zero, and are easily tuned across the IR and visible ranges.

No MeSH data available.


Related in: MedlinePlus

Fabrication of Au wire woodpiles.(a), PSS film imprinted with ETFE grating, shadow deposition of Au wires, and polymer film spin-cast over wires. (b), Wire grating film released and collected onto another grating film at 90°, (c), bilayer grating film released and stacked/rolled to form (d), multilayer woodpile. (e),(f),(g), SEM images of (e), flexible single wire layer, (f), bilayer Au wire grating film (angularly misaligned here) and (g), FIB-milled cross-section of woodpile with 8 bilayers. (h),(i), Optical white light images of (h), single layer, and (i), woodpile rolled onto a glass rod, grating period 556 nm.
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f1: Fabrication of Au wire woodpiles.(a), PSS film imprinted with ETFE grating, shadow deposition of Au wires, and polymer film spin-cast over wires. (b), Wire grating film released and collected onto another grating film at 90°, (c), bilayer grating film released and stacked/rolled to form (d), multilayer woodpile. (e),(f),(g), SEM images of (e), flexible single wire layer, (f), bilayer Au wire grating film (angularly misaligned here) and (g), FIB-milled cross-section of woodpile with 8 bilayers. (h),(i), Optical white light images of (h), single layer, and (i), woodpile rolled onto a glass rod, grating period 556 nm.

Mentions: Gold woodpiles are assembled by stacking large-area polymer films coated in gratings of metal wires, using a simple technique in which the films are captured onto a water surface and then stacked, rolled or folded in customisable orientations to build up an arbitrary number of layers (Fig. 1a–d)22. Gratings are first imprinted into a layer of sacrificial polymer, polystyrene sulfonic acid (PSS). Gold is then deposited at glancing angle on top of the PSS grating so that distinct wires are created from shadowing [Fig. 1(a,e,f)], producing nanowires as narrow as 50 nm with thickness 30 nm that span many cm in length.


Optical nano-woodpiles: large-area metallic photonic crystals and metamaterials.

Ibbotson LA, Demetriadou A, Croxall S, Hess O, Baumberg JJ - Sci Rep (2015)

Fabrication of Au wire woodpiles.(a), PSS film imprinted with ETFE grating, shadow deposition of Au wires, and polymer film spin-cast over wires. (b), Wire grating film released and collected onto another grating film at 90°, (c), bilayer grating film released and stacked/rolled to form (d), multilayer woodpile. (e),(f),(g), SEM images of (e), flexible single wire layer, (f), bilayer Au wire grating film (angularly misaligned here) and (g), FIB-milled cross-section of woodpile with 8 bilayers. (h),(i), Optical white light images of (h), single layer, and (i), woodpile rolled onto a glass rod, grating period 556 nm.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4321162&req=5

f1: Fabrication of Au wire woodpiles.(a), PSS film imprinted with ETFE grating, shadow deposition of Au wires, and polymer film spin-cast over wires. (b), Wire grating film released and collected onto another grating film at 90°, (c), bilayer grating film released and stacked/rolled to form (d), multilayer woodpile. (e),(f),(g), SEM images of (e), flexible single wire layer, (f), bilayer Au wire grating film (angularly misaligned here) and (g), FIB-milled cross-section of woodpile with 8 bilayers. (h),(i), Optical white light images of (h), single layer, and (i), woodpile rolled onto a glass rod, grating period 556 nm.
Mentions: Gold woodpiles are assembled by stacking large-area polymer films coated in gratings of metal wires, using a simple technique in which the films are captured onto a water surface and then stacked, rolled or folded in customisable orientations to build up an arbitrary number of layers (Fig. 1a–d)22. Gratings are first imprinted into a layer of sacrificial polymer, polystyrene sulfonic acid (PSS). Gold is then deposited at glancing angle on top of the PSS grating so that distinct wires are created from shadowing [Fig. 1(a,e,f)], producing nanowires as narrow as 50 nm with thickness 30 nm that span many cm in length.

Bottom Line: Previous routes use electron-beam lithography or direct laser writing but widespread application is restricted by their expense and low throughput.Control of stacking sequence, asymmetry, and orientation elicits great control, with visible-wavelength band-gap reflections exceeding 60%, and with strong induced chirality.Such flexible and stretchable architectures can produce metamaterials with refractive index near zero, and are easily tuned across the IR and visible ranges.

View Article: PubMed Central - PubMed

Affiliation: NanoPhotonics Centre, Cavendish Laboratory, Department of Physics, JJ Thompson Ave, University of Cambridge, Cambridge, CB3 0HE, UK.

ABSTRACT
Metallic woodpile photonic crystals and metamaterials operating across the visible spectrum are extremely difficult to construct over large areas, because of the intricate three-dimensional nanostructures and sub-50 nm features demanded. Previous routes use electron-beam lithography or direct laser writing but widespread application is restricted by their expense and low throughput. Scalable approaches including soft lithography, colloidal self-assembly, and interference holography, produce structures limited in feature size, material durability, or geometry. By multiply stacking gold nanowire flexible gratings, we demonstrate a scalable high-fidelity approach for fabricating flexible metallic woodpile photonic crystals, with features down to 10 nm produced in bulk and at low cost. Control of stacking sequence, asymmetry, and orientation elicits great control, with visible-wavelength band-gap reflections exceeding 60%, and with strong induced chirality. Such flexible and stretchable architectures can produce metamaterials with refractive index near zero, and are easily tuned across the IR and visible ranges.

No MeSH data available.


Related in: MedlinePlus