Light trapping in thin film solar cells using a polarization independent phase gradient metasurface

In this paper, we use a polarization independent phase gradient metasurface to trap sunlight inside a thin film solar cell. In this method, the metasurface is placed at the bottom of the solar cell to anomalously reflect light rays of Sun and prevent them from escaping the cell. The performance of the proposed structure is numerically studied at different wavelengths as well as different angles of incidence, for both TM and TE polarizations. The numerical results show absorption enhancement in a wide range of wavelengths, and short circuit current improvement for both TM and TE polarizations.