Laser-Scribing Optimization for Sprayed SnO₂-Based Perovskite Solar Modules on Flexible Plastic Substrates

Flexible perovskite solar cells (FPSCs) are prime candidates for applications requiring a highly efficient, low-cost, lightweight, thin, and even foldable power source. Despite record efficiencies of lab-scale flexible devices (19.5% on a 0.1 cm² area), scalability represents a critical factor toward commercialization of FPSCs. Large-area automized deposition techniques and efficient laser scribing procedures are required to enable a high-throughput production of flexible perovskite modules (FPSMs), with the latter being much more challenging compared to glass substrates. In this work, we introduce the combined concept of laser scribing optimization and automatized spray-coating of SnO₂ layers. Based on a systematic variation of the incident laser power and a comprehensive morphological and electrical analysis of laser-based cell interconnections, optimal scribing parameters are identified. Furthermore, spray-coating is used to deposit uniform compact SnO₂ films on large-area (>120 cm²) plastic substrates. FPSCs with spray-coated SnO₂ show comparable performance as spin-coated cells, delivering up to 15.3% efficiency on small areas under 1 sun illumination. When upscaling to large areas, FPSMs deliver 12% power conversion efficiency (PCE) and negligible hysteresis on 16.8 cm² and 11.7% PCE on a 21.8 cm² active area. Our perovskite devices preserved 78% efficiency when the active area increased from 0.1 to 16.8 cm², demonstrating that our combined approach is an effective strategy for large-area manufacturing of perovskite devices on flexible substrates.