Level Set-Based Topology Optimization for the Design of Light-Trapping Structures

This paper discusses a systematic design method for light-trapping structures that can enhance the absorption capability of thin-film solar cells. Light-trapping techniques extend the length of the light path in the active layer and thereby enhance solar cell efficiency. The level set-based topology optimization method is constructed for the structural design of a light-scattering layer that is in contact with a cladding layer above the active layer. The optimization problem is formulated to maximize the light absorption coefficient of the solar cells. Numerical results demonstrate that the optimization can successfully find an appropriate configuration of the dielectric material and air for a light-scattering layer that enhances the light absorption coefficient at the desired wavelength.