Efficient Rigid and Flexible Perovskite Photovoltaics with Crystallization and Morphology Evolution via Chlorine-Containing Triazine Molecular Passivation

The photovoltaic performance of perovskite solar cells (PSCs) depends on the crystallization of the perovskite. Achieving a crystalline perovskite with large grains and ordered lattices remains a challenge. Herein, we employ 2-amino-4,6-dichlorotriazine to facilitate grain growth. The molecular dipole passivation reduces the undercoordinated lead (Pb) defects and iodine (I) vacancy defects, and it corrects the PbI 6 4− octahedral distortion, thereby leading to the achievement of the microscale grains and ordered (110) lattice arrangement. The rigid PSCs yield a power conversion efficiency (PCE) of 26.58% and an enhanced operational stability. Furthermore, it enables a flexible PSC with a PCE of 24.29%. This work provides a molecular dipole passivation to induce large perovskite grains and ordered lattice arrangements for high-performance PSCs.