Neutralizing Charge Centers Radius via Dipole-Charge Interaction in Perovskites

Organic-inorganic perovskite materials face challenges related to the presence of non-neutralized charge centers, such as positively charged local defects arising from lattice imperfections like point-vacancies and under-coordinated lead ions at lattice edges, hindering their photoelectric intrinsic properties. We introduce 3,3-difluoropyrrolidine hydrochloride (GOSO-005), a novel dipolar molecule, as an effective solution for neutralizing positive charge centers within perovskites. GOSO-005, with its high dipole moment and fluorinated groups, interacts with charged defects to neutralize them, thus reducing defect density and minimizing the effective electron-capturing radius. This neutralizing strategy enhances charge transport, reduces Shockley-Read-Hall recombination, and boosts an impressive efficiency of 26.09% (certified 26.12%) for perovskite solar cells. In parallel, the fluorinated dipolar molecule introduces additional hydrophobicity to the resultant perovskite, thereby significantly enhancing the long-term environmental, continuous illumination operational, and thermal stabilities of the perovskite solar cells.