Incubating High-Quality Perovskite Film via Facial Mask Technique for Efficient and Stable Solar Cells

摘要

High-performance perovskite film with superior internal and surface qualitiesis critical for perovskite solar cells (PSCs) but hardly achievable dueto the rapid crystallization rate of perovskite itself. Herein, a novel techniqueby in situ manipulating perovskite crystal growth and modifying thesurface properties is developed using organic passivating agent-assistedpolydimethylsiloxane membrane as a facial mask (FM) of perovskites. Byplacing the perovskite-precursor films with their faces toward the designedFM during thermal annealing, a favorable microenvironment is constructedfor incubating high-quality perovskite films with smooth surface,enhanced vertical orientation of (100) plane, and well-adjusted interfacialenergy levels. With this versatile FM incubation technique, efficient PSCsfor both methylammonium (MA)-based and formamidinium (FA)-MA-Csmixed perovskite systems are facilely fabricated, delivering excellenthumidity/thermal stabilities and promising efficiencies up to 21.4% withan improved open-circuit voltage of 1.15 V in MA-based devices. This studynot only provides a facile and efficient approach to rationally manage theperovskite growth process, but also reveals the fundamental characteristicsof high-quality perovskite films comprehensively for the constructionof efficient and stable PSCs.