High-performance inverted perovskite solar cells and modules via aminothiazole passivation†

Abstract

The passivation of undesirable defects in the perovskite light-absorption layer is an essential and effective strategy for improving the performance of perovskite solar cells (PSCs). Herein, a novel additive, 5-aminothiazole hydrochloride (5ATCl), possessing both electron-accepting (NH₃⁺) and electron-donating (CN) functional groups, is introduced into the perovskite precursor ink, enabling holistic improvements of perovskite thin-film quality and photovoltaic performance. Comprehensive theoretical calculations and experimental characterizations reveal strong hydrogen bonds and intermolecular coordination between 5ATCl with the perovskite components. Consequently, the perovskite films demonstrate increased grain size and improved film quality, along with a released residual stress and a reduced defect density. Furthermore, the 5ATCl contributes to a favorable energy level alignment, thus promoting charge transfer and minimizing open-circuit voltage loss of the resulting devices. Notably, the champion power conversion efficiencies (PCEs) of the rigid and flexible PSCs with the incorporation of 5ATCl reach 26.38% (certified 25.87%) and 24.54%, respectively. The stability of the devices is also enhanced, demonstrating a T₉₀ lifetime of 850 hours under continuous light illumination at maximum power point tracking. Additionally, centimeter-sized PSCs and 5 cm × 5 cm solar mini-modules also demonstrate impressive PCEs of 24.86% and 21.72% respectively, indicating the great feasibility of our strategy in up-scaling device fabrication.