Covalent Organic Framework as a Precursor Additive Toward Efficient and Stable Perovskite Solar Cells

In recent years, there has been significant progress in the use of organic-inorganic hybrid perovskites for photovoltaic applications. Engineering the compositions and/or morphology of perovskites has become the most effective method to address the challenges related to photovoltaic efficiency and stability. Herein, an amino-functionalized covalent organic framework (NH2-COF) as a precursor additive to modulate the crystallization of perovskites is incorporated. The NH2-COF is found to decrease the defect concentration, reduce the nonradiative recombination within the perovskite layer, and further promote carrier transport. Correspondingly, the solar cells based on the NH2-COF-modified perovskites deliver a champion power conversion efficiency of 22.13% with a fill factor of 0.773 under AM 1.5G 100 mW cm-2 illumination. Furthermore, the device retains approximately 81% of its initial efficiency after 1000 h of aging under ambient conditions at a temperature of 30 degrees C and relative humidity ranging from 45% to 55%. It is believed that this work would provide a facile and efficient strategy to prepare high-quality perovskite films for efficient and stable solar cells. A strategy to fabricate high-performance perovskite solar cells using an amino-functionalized covalent organic framework (NH2-COF) as a precursor additive is reported, and the optimized perovskite films exhibit reduced defects and a best power conversion efficiency of 22.13% together with enhanced long-term moisture stability is achieved in perovskite solar cells.image (c) 2023 WILEY-VCH GmbH