Optical Management of Perovskite Solar Cells by Biomimetic‐Structured Polydimethylsiloxane Films

The application of antireflective (AR) films is a promising optical management strategy to improve the light utilization of perovskite solar cells (PSCs). Plumeria petals of different colors are employed as the master mold for the first time to prepare biomimetic AR films. Hierarchical morphologies replicated from the petals have a primary characteristic size in tens of micrometer scale. A strong scattering effect happens when the incident light hits the AR films, leading to a remarkably reduced reflectance with broadband enhancement of the transmission over the entire visible range. With the incorporation of the biomimetic AR film, the highest power conversion efficiency for PSCs reaches 23.56% with a large short‐circuit density ( J _sc ) of 26.54 mA cm ⁻² , corresponding to an average enhancement of 6.17%. The enhancement effect is verified under 1.5G AM radiation with different tilted angles and warm white LED light source with different light intensities. Furthermore, optical simulations are performed to illustrate the structure–effective relationship. This work offers an interesting experience by learning from nature and provides valuable references for further refining the design of the AR films in micrometer scale.