Advances and strategies in scalable coating techniques for flexible perovskite solar cells

Abstract

Perovskite solar cells (PSCs) have emerged as leading candidates for next-generation photovoltaics owing to their outstanding power conversion efficiencies (PCEs), low-cost materials, and compatibility with low-temperature, solution-based fabrication techniques. While certified PCEs of 27.0% have been reached on rigid substrates, transitioning to scalable, flexible architectures introduces new challenges. This review highlights recent advancements in flexible PSCs (F-PSCs), including the development of low-temperature-processed charge transport materials, flexible transparent electrodes, and encapsulation strategies that maintain mechanical robustness under deformation. Scalable deposition techniques, such as blade coating, slot-die coating, and spray coating, are also discussed, with respect to film uniformity, process control, and compatibility with roll-to-roll (R2R) manufacturing. The integration of solvent and additive engineering, along with interfacial modifications, is shown to be critical in optimizing film morphology and enhancing device performance. Notably, recent studies report flexible perovskite modules achieving PCEs exceeding 17% across active areas larger than 100 cm². Beyond the PCE, this review addresses critical issues in ensuring long-term operational stability, including mechanical reliability and environmental degradation from moisture, oxygen, light, and thermal stress. Strategies such as multi-cation perovskite formulations, advanced interfacial modification, and high-barrier encapsulants are evaluated for their role in enhancing long-term operational stability. Finally, we provide a forward-looking perspective on the technical gaps and collaborative efforts required, across materials science, engineering, and industrial scale-up, to enable the commercial application of F-PSCs.