Enhancing light pressure via localized surface plasmon resonance through randomly nickel nano-roughness

In this study, we designed an energy harvesting technique, which is beyond the traditional methods of solar energy utilisation (solar cells, etc), based on the radiation pressure used in optical tweezers or solar sails. To increase the intensity of the radiation pressure, we fabricated the GaAs wafer in the form of a volcanic crater structure, which is a light-collecting structure. Then, Pb(Zr0.52,Ti0.48)O3, which are piezoelectric materials, and Ni metal were sequentially formed therein. The fabricated structure made it possible to substantially increase the light intensity by generating surface plasmon resonance through scattering with laser light and numerous Ni nano-roughness formed on the Ni metal surface. This increased light intensity immediately acts as a pressure and deforms the structure of Pb(Zr0.52,Ti0.48)O3, allowing us to obtain a current of up to 40 nA from 401 nm wavelength laser. We analysed the light enhancement using the surface-enhanced Raman scattering phenomenon. Moreover, through finite-difference time-domain and COMSOL multiphysics simulations, we confirmed that these experimental results are due to the strong effect of surface plasmon resonance by nano-roughness.