In Air High-Efficiency and Stable Perovskite Solar Cells Module Assisted by Polymer Internal Encapsulation

The preparation of traditional organic-inorganic lead-halogen hybrid perovskite solar cells often requires strict nitrogen glove box conditions, hindering their industrial scalability. This study aimed to explore the development of a large-area perovskite film formation process and design a novel device structure to achieve a dual enhancement of module device efficiency and stability in a high humidity air environment (55%). High-quality perovskite thin films were successfully prepared by vacuum extraction in ambient air, followed by a double-end low-temperature photopolymerization process utilizing acrylate monomer molecules for inner encapsulation modification of the freshly formed perovskite thin films. The impact of these techniques on the photoelectric characteristics of perovskite thin films and devices was investigated. The results indicated that uniform and dense perovskite films could be achieved in ambient air with a pumping time of 60 seconds. By adjusting the concentration of ethylene glycol dimethacrylate monomer molecules used in the low-temperature photopolymerization process, surface defects on the perovskite film could be effectively controlled. The optimal concentration of 1 mg/ml resulted in perovskite films with optimal morphology and fluorescence intensity. Furthermore, rigid and flexible module devices (effective area: 18 cm²), based on the polymer inner encapsulation, demonstrated outstanding outdoor photoelectric conversion efficiencies of 19.51% and 18.17%, respectively (with the highest indoor low-light conversion efficiencies of 25.13% and 30.2%, respectively). Notably, the untreated flexible devices exhibited a significant decline in photoelectric conversion efficiency, falling below 50% of the initial value after one month of exposure to air. In contrast, devices incorporating the polymer inner encapsulation layer maintained over 90% of their original efficiency, highlighting their excellent humidity resistance stability. Moreover, the polymer encapsulation layer also greatly improved the bending stability of the flexible devices. This research paved avenue for the industrial-scale production of perovskite solar cells, addressing the challenges associated with humidity and large-area fabrication. The findings contribute to the advancement of perovskite solar cell technology, offering a pathway for high-efficiency and stable devices suitable for real-world applications.