Combined evaporation-solution methodology for high-efficiency perovskite solar cells with exceptional reproducibility†

Abstract

Currently, the highest-performance perovskite solar cells are predominantly fabricated using solution-based techniques, such as spin coating, blade coating, and slot-die coating. However, the complex chemical properties of the perovskite precursors' solution pose significant challenges to the scalable and reproducible production of high-quality devices. Although vacuum-based deposition is a well-established approach for thin film fabrication, the high vapor pressure of organic ammonium halides complicates the evaporation process in hybrid organic–inorganic perovskites. Moreover, prolonged deposition times and persistent difficulties in rapidly forming high-quality perovskite films remain critical obstacles. In this work, we combine vacuum-based deposition of lead iodide with solution processing of organic ammonium halide to prepare large-grain perovskite films with high reproducibility. The resulting PSCs achieve a power conversion efficiency (PCE) of 21.55% (certified at 22.1%). Furthermore, substrate modification with aluminium oxide (Al₂O₃) and the incorporation of inorganic components such as CsCl and PbCl₂ enable the evaporation of the lead iodide layer within five minutes, yielding high-quality perovskite films. To the best of our knowledge, this approach delivers one of the highest PCEs reported to date for inverted (p–i–n) PSCs by combined evaporation-solution methodology.