Crystallinity Control and Strain Release in Wide-Bandgap Perovskite Film via Seed-Induced Growth for Efficient Photovoltaics.

The seed method stands out as a straightforward and efficient approach for fabricating high-performance perovskite solar cells (PSCs). In this study, we propose the utilization of an antisolvent as an additive to induce crystal seeding, thereby facilitating the growth of wide-bandgap perovskite grains. Specifically, we introduce three commonly used antisolvents─ethyl acetate (EA), isopropanol (IPA), and chlorobenzene (CB)─directly into the perovskite precursor solution to generate perovskite seeds, which serve to promote subsequent nucleation. This antisolvent-crystal seeding method (ACSM) results in increased grain sizes, reduced film defects, and overall improved film quality. Consequently, the power conversion efficiencies ( PCE s) of 1.647 eV PSCs with EA, IPA, and CB additives are recorded at 19.86%, 20.61%, and 20.45%, respectively, surpassing that of the reference device with a PCE of 18.83%. Furthermore, the stability of the PSCs prepared through ACSM is notably enhanced. Notably, PSCs optimized with IPA retain 75% of the original PCE after being stored in ambient air conditions (25 °C, RH ∼ 15%) for 30 days, better than the CB-added (64%) and the EA-added devices (53%), while the reference devices only retain 31% of the initial PCE . Moreover, even after continuous thermal annealing at 50 °C for 200 h, IPA-assisted devices demonstrate the best stability, followed by those with CB and EA, with the reference exhibiting the poorest stability.