Enhancing High-Quality Perovskite Films via Investigation of <mml:mstyle>PbI</mml:mstyle>2 Crystallization at Different Pre-Annealing Temperatures

The two-step blade coating process, recognized for its simplicity and compatibility with large-area production, is a key technology for fabricating high-quality perovskite films. Achieving high-quality perovskite films depends on the crystallization quality of lead iodide films. Unlike spin coating, the solvent evaporation mechanism in blade coating induces a rapid crystallization rate of lead iodide, resulting in poor crystallization quality that negatively impacts the optoelectronic conversion efficiency of perovskite solar cells. This study shows that incorporating a 35 degrees C substrate pre-annealing (SP) step effectively mitigates the rapid crystallization issue of lead iodide. With this approach, the power conversion efficiency (PCE) of a 1cm2 perovskite solar cell reaches 16.15%, demonstrating excellent stability.