An extremely high localized surface plasmon resonance (LSPR) is generated at the small gap between a gold (Au) nanoparticle and an Au thin film. The conventional LSPR of the film-coupled nanoparticle gives a narrow bandwidth, and it causes low efficiency from the energy harvesting point of view. In this study, we obtained a primary shape of the nanoparticle that works for the field enhancement in the broadband visible spectrum by using topology optimization combined with the concept of the probability density function. We confirmed that the derived elliptical hole and the thin layer at the lower nanoparticle part lead to a broad visible spectrum from blue to red range.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy (miscellaneous)