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Plasmonic effects of various sized Al nanospheres non-embedded on Ta2O5 antireflective–coated single-junction GaAs solar cells are analyzed by finite difference time domain (FDTD) simulations. The impact of optimized plasmonic nanoparticles is further analyzed for embedded Al nanospheres in GaAs and compared with nanoparticles at back contact. It is found that the nanoparticles of radius 30 nm show superior spectral response in comparison with other radii for non-embedded design. Further, non-embedded optimized nanoparticles show better spectral response when embedded in GaAs layer 10 nm below the Ta2O5 antireflection layer, which yields a maximum current density of 28.17 mA/cm2. Moreover, photovoltaic current–voltage characteristics were studied to confirm the performance enhancement induced by Al nanoparticle plasmons. The power conversion efficiency enhancement of 5.4, 11.5, and 2.3% for optimized radius of 30 nm in non-embedded, embedded (at optimized depth of 10 nm), and at rear surface, respectively, were found compared to Ta2O5-coated single-junction GaAs solar cells. [ABSTRACT FROM AUTHOR]

Hollow metal nanostructures are fascinating because of their unique and surrounding environment-sensitive localized surface plasmon resonances (LSPRs). Herein, we have investigated the hollow silver nanoshell (HSN) sensitivity of different inner core radii and shell thicknesses with respect to change in surrounding medium refractive index. Also, we have shown that the extinction peak of HSNs can be fine-tuned in the visible region as well as biological windows by manipulating the size parameters. Moreover, an enhancement in refractive index sensitivity of 133 to 283 nm/RIU can be achieved in the biological windows by thick hollow silver nanoshells in comparison to thin ones. To achieve a comprehensive study, the sensitivity of homogeneous LSPR extinction inflection points with change in refractive index is also investigated. A consistent improvement in bulk refractive index sensitivity of 36% and 15% is predicted with thick and thin shell layers, respectively. Finally, thick HSNs showed higher refractive index sensitivity when compared with thin ones. Moreover, we envision the idea of more than one molecule detection by tracking the curvature changes. Therefore, we provide a deeper insight into the refractive index sensitivity of homogeneous LSPR inflection points for their use in LSPR-based sensors. [ABSTRACT FROM AUTHOR]

Localized surface plasmon resonance (LSPR) for longitudinal mode of gold nanorod is simulated by using Gans theory. The parameters like surface scattering, radiation damping, and dynamic depolarization of radiation across the surface of nanorod affecting response of free electrons towards optical excitation are considered. Simulation results show that refractive index sensitivity linearly rises with size and aspect ratio, whereas this leads to the broadening of resonant line width also. Therefore, to optimize the size of nanorod, figure of merit (FOM) is calculated and observed that optimized width is 15 nm for an aspect ratio of 2, whereas it is 12 nm for aspect ratios 3 and 4. Further, optimization by using newly modified figure of merit (MFOM) shows that optimized width is 39 nm for aspect ratio of 2 and 24 nm for 3 and 4 aspect ratios. It is also found that at aspect ratio 2, both FOM and MFOM are higher than the aspect ratios 3 and 4. The quality factor calculation for LSPR response of nanorod explains its dependence with aspect ratio and optimized dimensions. [ABSTRACT FROM AUTHOR]