Synergistic Crystallization Regulation by Substituent Electronic Effects of Polyfluoroarenes Toward Large Area Perovskite Solar Module Fabrication

Achieving uniform and high-quality perovskite crystallization across large substrates is a prerequisite for transitioning perovskite solar cells (PSCs) from laboratory scale to industrial production. Herein, we systematically regulate perovskite crystallization kinetics by using polyfluoroarene molecules featured with distinct electronic effects. We demonstrate that 3,4,5-trifluorobenzonitrile (TFBN) containing a strong electron-withdrawing cyano group creates an electron-deficient conjugation system. This configuration enhances anion-π interactions with I⁻ and forms strong coordination with Pb²⁺ framework. Synergizing with intermolecular hydrogen bonding, TFBN increases the effective nucleation barrier, converting rapid nucleation into a controlled, uniform growth process. Consequently, this multidimensional regulation yields pinhole-free perovskite films with significantly suppressed non-radiative recombination. The TFBN-optimized small area device (aperture area: 0.09 cm²) achieves a champion power conversion efficiency (PCE) of 27.01% along with a low non-radiative voltage loss of only 55 mV. Furthermore, we demonstrate excellent scalability, achieving PCEs of 25.56% for 1 cm² (aperture area) cells, 24.51% for 14.63 cm² (active area) modules, and 21.05% for 58.51 cm² (active area) modules, respectively. Moreover, the resulting devices exhibit improved long-term operational stability under maximum power point tracking and thermal stress. Overall, this synergistic regulation approach provides molecular-level design principles for scalable fabrication of efficient and durable perovskite photovoltaics.