Improved Lead Halide Perovskite Films and Devices Using Hot-Flow-Assisted Annealing

Physical and chemical controlling of the lead halide perovskite films is crucial to minimize defects and improve overall performance and stability of perovskite solar cells. In this study, applying a hot flow of dry air on the surface of perovskite films during hot plate annealing is investigated. We found that this technique leads to a smooth texture and reduces the surface defects. A hot dry airflow of 15 L/min improves the power conversion efficiency from 13.56% to 15.31%, with approximately 4.3% and 10.4% enhancement of fill factor and short-circuit current density, respectively. However, increasing the rate of dry airflow leads to large voids, which is a critical concern for leakage current and performance degradation.