Recent progress in meniscus coating for large-area perovskite solar cells and solar modules
Perovskite solar cells (PSCs) have attracted increasing attention in the past decade due to their outstanding photovoltaic performances. However, previous researches mainly focused on small-area PSCs, which do not meet the demand for large-scale production and commercial applications. Commonly used spin coating in small-area PSCs is not suitable; whereas meniscus coating is becoming the most promising scalable technique for fabricating large-area PSCs due to its special advantages. In this review, we first introduce the structure and advantages of meniscus coating. In particular, we explain the nucleation and crystal growth process of perovskite during the meniscus coating process. Then we systematically analyze the key factors for improving the photovoltaic performances and stability of large-area PSCs. With an understanding of the key factors, we summarize a number of strategies for fabricating large-area PSCs with high efficiency and stability based on meniscus coating. The strategies include optimizing the crystallinity and morphology of perovskite films, use of additives, chemical composition engineering of perovskite, interfacial engineering, use of 2D perovskite, optimization of the charge transport layers, barrier designs and encapsulations. We believe that meniscus coating will be the most important and efficient approach for fabricating large-area PSCs and pave the way to commercialization of PSCs in the future.