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Au nanostructure arrays for plasmonic applications: annealed island films versus nanoimprint lithography.

Lopatynskyi AM, Lytvyn VK, Nazarenko VI, Guo LJ, Lucas BD, Chegel VI - Nanoscale Res Lett (2015)

Bottom Line: Modelling of the optical response for nanostructures with typical shapes associated with these techniques (parallelepiped for NIL and semi-ellipsoid for annealed island films) was performed using finite-difference time-domain calculations.As an important point, the distribution of electric field at so-called 'hot spots' was considered.The application of island film thermal annealing method for nanochips fabrication can be considered as a possible cost-effective platform for various surface-enhanced spectroscopies; while the NIL-fabricated NSA looks like more effective for sensing of small-size objects.

View Article: PubMed Central - PubMed

Affiliation: Department of Functional Optoelectronics, V. E. Lashkaryov Institute of Semiconductor Physics NASU, 41 Nauki avenue, 03028 Kyiv, Ukraine.

ABSTRACT
This paper attempts to compare the main features of random and highly ordered gold nanostructure arrays (NSA) prepared by thermally annealed island film and nanoimprint lithography (NIL) techniques, respectively. Each substrate possesses different morphology in terms of plasmonic enhancement. Both methods allow such important features as spectral tuning of plasmon resonance position depending on size and shape of nanostructures; however, the time and cost is quite different. The respective comparison was performed experimentally and theoretically for a number of samples with different geometrical parameters. Spectral characteristics of fabricated NSA exhibited an expressed plasmon peak in the range from 576 to 809 nm for thermally annealed samples and from 606 to 783 nm for samples prepared by NIL. Modelling of the optical response for nanostructures with typical shapes associated with these techniques (parallelepiped for NIL and semi-ellipsoid for annealed island films) was performed using finite-difference time-domain calculations. Mathematical simulations have indicated the dependence of electric field enhancement on the shape and size of the nanoparticles. As an important point, the distribution of electric field at so-called 'hot spots' was considered. Parallelepiped-shaped nanoparticles were shown to yield maximal enhancement values by an order of magnitude greater than their semi-ellipsoid-shaped counterparts; however, both nanoparticle shapes have demonstrated comparable effective electrical field enhancement values. Optimized Au nanostructures with equivalent diameters ranging from 85 to 143 nm and height equal to 35 nm were obtained for both techniques, resulting in the largest electrical field enhancement. The application of island film thermal annealing method for nanochips fabrication can be considered as a possible cost-effective platform for various surface-enhanced spectroscopies; while the NIL-fabricated NSA looks like more effective for sensing of small-size objects.

No MeSH data available.


Related in: MedlinePlus

Calculated values of average electric field intensity enhancement within a 25-nm vicinity of differently shaped Au nanoparticles. Simulation results correspond to (a) semi-ellipsoid- and (b) parallelepiped-shaped Au nanoparticles on glass substrates. Effective geometrical parameters of Au nanoparticles used in FDTD modelling are the same for semi-ellipsoid and parallelepiped shapes and correspond to the data presented in Table 1 for samples R1 to R9, respectively. Labels above the bars indicate the light wavelength, which the maximal electric field intensity enhancement for specific nanoparticle geometry was obtained at.
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Fig8: Calculated values of average electric field intensity enhancement within a 25-nm vicinity of differently shaped Au nanoparticles. Simulation results correspond to (a) semi-ellipsoid- and (b) parallelepiped-shaped Au nanoparticles on glass substrates. Effective geometrical parameters of Au nanoparticles used in FDTD modelling are the same for semi-ellipsoid and parallelepiped shapes and correspond to the data presented in Table 1 for samples R1 to R9, respectively. Labels above the bars indicate the light wavelength, which the maximal electric field intensity enhancement for specific nanoparticle geometry was obtained at.

Mentions: The whole set of maximal electric field enhancement values obtained for each of the nanoparticle geometries is presented in Figure 7. It is evident that the largest enhancement values are exhibited when equivalent diameters of both types of nanoparticles range from 85 to 143 nm and the height of nanoparticles is 35 nm. These optimized geometrical parameters can be used for manufacturing purposes to fabricate Au NSA providing plasmonic enhancement for different applications. For a defined nanoparticle shape and geometrical parameters, maximal electric field intensity enhancement is obtained at a specific light wavelength, which was found to range from about 620 nm (for small nanoparticles) to near infrared region (for large nanoparticles). Detailed light wavelength values are contained in labels in Figures 6, 7, and 8.Figure 7


Au nanostructure arrays for plasmonic applications: annealed island films versus nanoimprint lithography.

Lopatynskyi AM, Lytvyn VK, Nazarenko VI, Guo LJ, Lucas BD, Chegel VI - Nanoscale Res Lett (2015)

Calculated values of average electric field intensity enhancement within a 25-nm vicinity of differently shaped Au nanoparticles. Simulation results correspond to (a) semi-ellipsoid- and (b) parallelepiped-shaped Au nanoparticles on glass substrates. Effective geometrical parameters of Au nanoparticles used in FDTD modelling are the same for semi-ellipsoid and parallelepiped shapes and correspond to the data presented in Table 1 for samples R1 to R9, respectively. Labels above the bars indicate the light wavelength, which the maximal electric field intensity enhancement for specific nanoparticle geometry was obtained at.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4385248&req=5

Fig8: Calculated values of average electric field intensity enhancement within a 25-nm vicinity of differently shaped Au nanoparticles. Simulation results correspond to (a) semi-ellipsoid- and (b) parallelepiped-shaped Au nanoparticles on glass substrates. Effective geometrical parameters of Au nanoparticles used in FDTD modelling are the same for semi-ellipsoid and parallelepiped shapes and correspond to the data presented in Table 1 for samples R1 to R9, respectively. Labels above the bars indicate the light wavelength, which the maximal electric field intensity enhancement for specific nanoparticle geometry was obtained at.
Mentions: The whole set of maximal electric field enhancement values obtained for each of the nanoparticle geometries is presented in Figure 7. It is evident that the largest enhancement values are exhibited when equivalent diameters of both types of nanoparticles range from 85 to 143 nm and the height of nanoparticles is 35 nm. These optimized geometrical parameters can be used for manufacturing purposes to fabricate Au NSA providing plasmonic enhancement for different applications. For a defined nanoparticle shape and geometrical parameters, maximal electric field intensity enhancement is obtained at a specific light wavelength, which was found to range from about 620 nm (for small nanoparticles) to near infrared region (for large nanoparticles). Detailed light wavelength values are contained in labels in Figures 6, 7, and 8.Figure 7

Bottom Line: Modelling of the optical response for nanostructures with typical shapes associated with these techniques (parallelepiped for NIL and semi-ellipsoid for annealed island films) was performed using finite-difference time-domain calculations.As an important point, the distribution of electric field at so-called 'hot spots' was considered.The application of island film thermal annealing method for nanochips fabrication can be considered as a possible cost-effective platform for various surface-enhanced spectroscopies; while the NIL-fabricated NSA looks like more effective for sensing of small-size objects.

View Article: PubMed Central - PubMed

Affiliation: Department of Functional Optoelectronics, V. E. Lashkaryov Institute of Semiconductor Physics NASU, 41 Nauki avenue, 03028 Kyiv, Ukraine.

ABSTRACT
This paper attempts to compare the main features of random and highly ordered gold nanostructure arrays (NSA) prepared by thermally annealed island film and nanoimprint lithography (NIL) techniques, respectively. Each substrate possesses different morphology in terms of plasmonic enhancement. Both methods allow such important features as spectral tuning of plasmon resonance position depending on size and shape of nanostructures; however, the time and cost is quite different. The respective comparison was performed experimentally and theoretically for a number of samples with different geometrical parameters. Spectral characteristics of fabricated NSA exhibited an expressed plasmon peak in the range from 576 to 809 nm for thermally annealed samples and from 606 to 783 nm for samples prepared by NIL. Modelling of the optical response for nanostructures with typical shapes associated with these techniques (parallelepiped for NIL and semi-ellipsoid for annealed island films) was performed using finite-difference time-domain calculations. Mathematical simulations have indicated the dependence of electric field enhancement on the shape and size of the nanoparticles. As an important point, the distribution of electric field at so-called 'hot spots' was considered. Parallelepiped-shaped nanoparticles were shown to yield maximal enhancement values by an order of magnitude greater than their semi-ellipsoid-shaped counterparts; however, both nanoparticle shapes have demonstrated comparable effective electrical field enhancement values. Optimized Au nanostructures with equivalent diameters ranging from 85 to 143 nm and height equal to 35 nm were obtained for both techniques, resulting in the largest electrical field enhancement. The application of island film thermal annealing method for nanochips fabrication can be considered as a possible cost-effective platform for various surface-enhanced spectroscopies; while the NIL-fabricated NSA looks like more effective for sensing of small-size objects.

No MeSH data available.


Related in: MedlinePlus