Improving Charge Extraction and Operational Stability in Inverted Perovskite Solar Cells with Conjugated Block Copolymers

Abstract A defect‐passivated, electronically benign interface is essential for high‐performance, stable perovskite solar cells (PSCs). Most conventional surface passivation strategies frequently introduce electrically resistive interlayers that compromise charge transport/extraction between the perovskite and charge‐transport layers. We resolve this challenge through the rational implementation of all‐conjugated block copolymers (CBCPs). The CBCPs demonstrate dual‐functional capabilities of offering charge transport channels while facile integrating multiple defect‐passivating moieties, thereby enabling efficient charge carrier transport and defect passivation. This dual‐functional synergy yielded a power conversion efficiency (PCE) of 26.11% in our best device. The target PSCs maintained >90% of their initial PCEs after maximum power point tracking for >1400 hours at 65 °C. This approach offers a promising strategy for interface engineering that improves both charge extraction and defect reduction using conjugated block copolymers.