Resonance-mediated dynamic modulation of perovskite crystallization for efficient and stable solar cells.

Manipulating perovskite crystallization to prepare high-quality perovskite films is the key to achieve highly efficient and stable perovskite solar cells (PSCs). Here, we report a dynamic strategy to modulate perovskite crystallization using a resonance hole-transporting material (HTM) capable of fast self-adaptive tautomerization between multiple electronic states with neutral and charged resonance forms for mediating perovskite crystal growth and defects passivation in situ. This approach, based on resonance variation with self-adaptive molecular interactions between HTM and perovskite, produces high-quality perovskite films with smooth surface, oriented crystallization and low charge recombination, leading to high-performance inverted PSCs with power conversion efficiencies approaching to 22% for small-area devices (0.09 cm2 ) and up to 19.5% for large-area devices (1.02 cm2 ). Also, remarkably high stability of the PSCs was observed, retaining over 90%, 88%, or 83% of the initial efficiencies in air with relative humidity of 40∼50%, under continuous one-sun illumination, or at 75°C annealing for 1000 h without encapsulation. This article is protected by copyright. All rights reserved.