Thiophene‐Bridged Conjugated Self‐Assembled Hole Transport Monolayer for Efficient and Stable Inverted Perovskite Solar Cells

Molecular engineering of self-assembled hole transport monolayer (SAM) has been proven as a crucial way to improve the performance of perovskite solar cells (PSCs). We report a thiophene-based conjugated SAM (MPA-Th-CA) for PSC through rational design to exploit superior conjugation and heteroatom effects. This SAM delivers multifaceted enhancements over its benzene-based counterpart (MPA-Ph-CA), featuring a larger dipole moment, improved conductivity, optimized energy level alignment with perovskite, more uniform substrate coverage, and promoted perovskite crystallization. Ultimately, devices based on MPA-Th-CA achieved an excellent power conversion efficiency of 25.53% and demonstrated markedly improved stability under long-term operation, high humidity, and high-temperature conditions. This work provides an important strategy for optimizing interfacial materials via conjugated molecular design to fabricate high-efficiency, stable PSCs.