Extinction spectra and electric field enhancement of silver chiral nano-flower shaped nanoparticle; comparison of discrete dipole approximation results with experimental results

Extinction Spectra and Electric Near-Field Distribution of Mn Nano-Rod Based Sculptured Thin Films: Experimental and Discrete Dipole Approximation Results

“…Figures 1, 2, and 3 show the results for helical structures with square, rectangle, and pentagon shapes, respectively. The optical spectra of all these structures for the s-polarized incident light at θ=10 and θ=70°w ere almost the same as it can be deduced from the DDA formalism [23][24][25] which is discussed in detail in our earlier work [17] (extinction spectra only depend on the electric field orientation and are not related to the propagation of incident wave). Therefore, only one set of these calculations (e.g., θ= 10°) is shown in Figs.…”

“…(iii) A number of plasmon oscillation peaks can be observed in these spectra [17,31]. In a glance, it may be concluded that structures with longer arms produce higher number of peaks which appear at longer wavelengths.…”

“…West et al [15] and Naik et al [16] who are members of the same research group in Purdue University have been working on finding alternative plasmonic materials to gold and silver and in their review papers, they have discussed on metals, metal-alloys, doped semiconductors, and graphene. However, the geometrical structure of nanoparticles from which the thin film is formed have a strong influence on the plasmonic properties although they may be made of the same material [12,13,17]. Therefore, we have taken a different route to the abovementioned research group to find an alternative way for obtaining plasmonic materials, namely using the sculptured thin films and produce different geometrical shapes and investigate the influence of shape on the plasmonic properties, irrespective of the material itself.…”

“…This method is used in many researches on the investigation of spectra from nanoparticles [10,13,17,26]. In our earlier work [17], we used the DDA method to calculate the extinction spectra for chiral nano-flower-shaped sculptured nanoparticles in different sizes and different symmetries (e.g., 3-, 4-and 5-fold symmetries) and extended the method to thin films formed of an assembly of these nanoparticles. In the present work, we have calculated the scattering cross-section of Mn nano-rods with different dimensions as single rod and combination of nano-rods joining at different angles at different incident light angles, using the DDA method.…”

Fabrication of graded helical square tower-like Mn sculptured thin films and investigation of their electrical properties: comparison with perturbation theory

“…Sculptured thin films consist of columnar structures that their growth direction is being controlled/changed by movement of substrate. Complex structures such as chiral nano-flower shaped sculptured thin films are produced and their optical properties are investigated both experimentally [9] and theoretically [10][11][12].…”