Laser induced spinodal dewetting of Ag thin films for photovoltaic applications

Abstract

Plasmonics is a promising approach to enhance light trapping properties of thin-film solar cells. Excitation of surface plasmons is characterised by a strong scattering and an enhancement of the electric field in the vicinity of the metal nanoparticle. These properties can be used to reduce the optical losses due to incident light reflection and to increase the optical absorption within the cell. Absorption can be enhancenced in the required wavelength region by tuning the surface plasmon resonance controlling the nanoparticle's size, shape, and local dielectric environment. Ag nanoparticles obtained by laser induced dewetting of metastable Ag thin films on SiO2 have been characterized. Size and characteristic patterning length dependency of nanoparticles on film thickness have been determined and spinodal dewetting has been identified as the process responsible for nanoparticle formation. The tunability of the plasmon resonance has been demonstrated through the manipulation of particle size and dielectric environment.