Towards High-Efficiency Photon Trapping in Thin-Film Perovskite Solar Cells Using Etched Fractal Metadevices

Reflective loss is one of the main factors contributing to power conversion efficiency limitation in thin-film perovskite solar cells. This issue has been tackled through several approaches, such as anti-reflective coatings, surface texturing, or superficial light-trapping metastructures. We report detailed simulation-based investigations on the photon trapping capabilities of a standard Methylammonium Lead Iodide (MAPbI(3)) solar cell, with its top layer conveniently designed as a fractal metadevice, to reach a reflection value R<0.1 in the visible domain. Our results show that, under certain architecture configurations, reflection values below 0.1 are obtained throughout the visible domain. This represents a net improvement when compared to the 0.25 reflection yielded by a reference MAPbI(3) having a plane surface, under identical simulation conditions. We also present the minimum architectural requirements of the metadevice by comparing it to simpler structures of the same family and performing a comparative study. Furthermore, the designed metadevice presents low power dissipation and exhibits approximately similar behavior regardless of the incident polarization angle. As a result, the proposed system is a viable candidate for being a standard requirement in obtaining high-efficiency perovskite solar cells.

Automated summary

Reflective loss is a major factor limiting the power conversion efficiency of thin-film perovskite solar cells. This issue can be addressed through various methods such as anti-reflective coatings, surface texturing, and superficial light-trapping metastructures. Our research focuses on the photon trapping capabilities of a standard MAPbI(3) solar cell with a fractal metadevice as the top layer, which achieves a reflection value of R<0.1 in the visible domain. Our findings show a significant improvement compared to a reference MAPbI(3) with a plane surface, which yields a reflection of 0.25 under identical simulation conditions. We also identify the minimum architectural requirements of the metadevice and compare it with simpler structures of the same family.