Roller Nanoimprinted Honeycomb Texture as an Efficient Antireflective Coating for Perovskite Solar Cells

The properly chosen light management strategy in perovskite solar cell devices is indispensable in achieving high power conversion efficiency. To diminish the reflection losses, texturization of the front surface, similar to what is used in established solar cell technologies, shall be taken into consideration. Within this paper, a honeycomb-like textured SU-8 photoresist layer is applied using a roller nanoimprint technique onto a planar perovskite solar cell to minimize reflection losses. The results show that the applied honeycomb pattern reduces the solar-weighted reflectance from 13.6% to 2.7%, which enhances the current density of the unmodified cell by 2.1 mA cm-2, outperforming the commonly used planar MgF2 antireflective coating by 0.5 mA cm-2. The experimental results are combined with optical modeling to find optimized structures and predict the optical behavior within a solar module. The process used within this work can be transferred to perovskite-silicon tandem solar cells, providing a promising pathway for the reflection reduction in future devices.