Loss Analysis of Halide‐Perovskite Solar Cells Deposited on Textured Substrates

To create efficient perovskite–silicon tandem cells with small pyramidal structures, it is crucial to deposit high‐quality wide‐bandgap perovskite films on textured surfaces. To attain this objective, it is essential to comprehensively understand the characteristics of perovskite films on textured surfaces and their impact on the efficiency loss mechanisms of perovskite solar cells. We find that the textured substrates provide better absorptance of the perovskite films, thus reducing the efficiency losses resulting from the reflected or transmitted light. The short‐circuit current of textured devices reaches 95% of the Shockley–Queisser limit at 1.68 eV. In addition, the fill factor losses are not obviously influenced by the textured bottom surface of the perovskite films. Furthermore, transient photoluminescence was used to quantify the recombination losses at open circuit in layer stacks and full devices, offering insights into the surface recombination velocity at the perovskite/electron transport layer interface and capacitive discharge of the electrodes.