Microtextured Light-Management Foils and Their Optimization for Planar Organic and Perovskite Solar Cells

Light management using microtextured foils on the top of planar organic and perovskite solar cells was investigated in detail by means of numerical simulations. Different texture shapes and sizes were analyzed and optimized with respect to the device performance, both under direct and diffuse illumination conditions. Tetrahedral texture with the aspect ratio of 0.78 was indicated as the optimal, enabling JSC boosts of 26.2% and 16.3% in the selected organic and perovskite cells, respectively. Furthermore, light management mechanisms enabled by the microtextured foil were identified, and each of them was studied and evaluated independently. Among them, the ability to internally trap the unabsorbed reflected light coming from the back side of the cell was revealed as the dominant one. Finally, the optical losses associated with a limited area of realistic prototype solar cells enhanced with microtextured foils were investigated. Results showed that in the selected solar cells, an area at least five times larger than the 2 × 2 mm ² area of the incident light beam is required in order to sufficiently suppress these losses and enable error-free experimental characterization of such devices.