Ink Design for Printing Perovskite Solar Cells and Modules

Printed metal halide perovskite photovoltaics combine high device performance with low-cost manufacturing, which have become one of the most promising candidates for next-generation photovoltaic technologies. With the rapid development of printing methods for scalable film deposition, printed perovskite solar cells have already achieved a power conversion efficiency (PCE) exceeding 26%. However, the PCE of commercial-size perovskite solar modules remains near 21%, indicating that the key bottleneck is no longer the intrinsic optoelectronic potential of the absorber but the translation of precursor inks into uniform, scalable, and durable films. During the printing process, ink design governs precursor solvent coordination, intermediate-phase evolution, colloidal stability, rheology, crystallization kinetics, wet-film stability, and ultimately large-area film quality. This Review summarizes perovskite precursor inks from a solution chemistry to manufacturing perspective and discusses the influences of chemical composition, solvent selection, mixed-solvent interactions, solvent-perovskite intermediates, crystallization control, solvent extraction methods, and rheological regulation on the film morphology during the scalable printing process. We further highlight industrially relevant metrics that increasingly determine viable ink systems, including shelf life, ambient air tolerance, coating-speed window, defect suppression, reproducibility, solvent toxicity, and compatibility with module integration and encapsulation. By linking ink formulation to film formation, scalable deposition, and module performance, this Review provides direction for printable ink design and identifies the critical challenges that should be addressed to realize reproducible, low-waste, high-throughput, and durable printed perovskite solar modules.