Printing‐Induced Alignment Network Design of Polymer Matrix for Stretchable Perovskite Solar Cells with Over 20% Efficiency

Abstract Polymer matrix is felicitously applied into the active layer and transporting layer of perovskite solar cells (PSCs) to enable a stretchable function. However, the chaotic deposition of polymer chains is the main cause for the inferior photoelectric performance. When the stretchable PSCs are in a working state, the stress cannot be removed effectively due to the random polymer chain deposition. The stress accumulation will cause irreversible damage to the stretchable PSCs. Herein, the structural bionics and patterned‐meniscus coating technology are combined to print the polymer chain‐oriented deposition in the stretchable PSCs. Based on this approach, the conducting polymer electrode is printed with both significant mechanical stability and conductivity. More importantly, the oriented polyurethane with self‐healing property can enhance the crystal quality of perovskite films and repair perovskite cracks caused by stress destruction. Thus, the corresponding stretchable PSCs achieve a stabilized power conversion efficiency (PCE) of 20.04% (1.0 cm 2 ) and 16.47% (9 cm 2 ) with minor efficiency discrepancy. Notably, the stretchable PSCs can maintain 86% of the primitive PCE after 1000 cycles of bending with a stretch ratio of 30%. This directional growth of polymer chain strategy provides guidance for printing prominent‐performance stretchable PSCs.