Oriented Growth for Efficient and Scalable Perovskite Solar Cells by Vapor-Solid Reaction

SUMMARYThe precise control and understanding of crystal orientation in perovskite polycrystalline films are crucial for the development of efficient and stable devices. However, achieving this control remains a significant challenge. Herein, we have developed a PbI2 oriented growth strategy, combining with in-situ vapor-solid reaction transformations, to achieve oriented growth of full-vacuum perovskite films. GIWAXS analysis revealed the general pattern of PbI2 oriented vapor growth and in-situ vapor-solid reaction transformation in this two-step process. The resulting preferred orientation has effectively reduced trap states density, optimizing the carrier dynamics. As a result, champion efficiencies of 22.11% (0.148 cm2), 20.60% (1 cm2) and 19.41% (5 × 5 cm2 mini-modules) are achieved, which are the highest value for perovskite based on vapor-solid reaction. Additionally, the oriented growth method is applicable to a variety of guide layers and is extended to 30 × 30 cm2 film, demonstrating the universality and scalability of the method.