Optimization of morphology of submonolayer metallic nanoparticles to enhance light trapping on a semiconductor surface

Abstract

The problem of light trapping engineering for semiconductor surfaces covered with randomly distributed spheroidal metallic nanoparticles has been considered. The absorption of incident light by such a structure has been calculated using the Green functions method, involving the concept of an effective susceptibility. A target function, optimizing broad-band light absorption throughout the visible range has been constructed taking the geometry of the structure as the control parameters. The optimization problem of light-trapping in such structure has been solved, and the optimum nanoparticle coverage for matching the required shape of absorption spectra has been obtained. Our results can be applied to the design of plasmonic-enhanced light-collecting elements in solar cells.