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

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.