All-blade-coated flexible perovskite solar cells & modules processed in air from a sustainable dimethyl sulfoxide (DMSO)-based solvent system

Flexible perovskite solar cells have been considered promising candidates for novel applications that require a high power-to-weight ratio. However, the scalable ambient air deposition of efficient devices remains a major challenge of this technology. In addition, toxic solvents are regularly used in perovskite layer deposition, which can damage the environment and endanger the safety of potential production lines. In this paper, we introduce sustainable flexible perovskite solar modules (flex-PSMs), in which all layers are deposited via blade coating in ambient air without the usage of toxic solvents. A double-cation Cs0.15FA0.85PbI3−xBrx-based perovskite is blade coated in two steps as the absorber and the coating parameters are optimized. We found that proper drying in the first step is crucial to obtain high-quality perovskite films with the right phase of the perovskite. We improved the morphology and limited the voids in the perovskite layer by additive engineering and obtained 14% efficiency. Finally, 94 cm2 modules were manufactured to demonstrate the scalability of the process.