Abstract
Commercialisation of perovskite photovoltaics (PV) hinges on scalable, environmentally responsible manufacturing; a challenge compounded by the widespread use of toxic solvents in current ink formulations. Here, we introduce a significantly reduced toxicity (SRT) solvent system for methylammonium lead iodide (MAPbI3) perovskite inks, specifically engineered for room-temperature, gas blowing assisted bar coating. Our formulation, based on ethanol and 2-methyltetrahydrofuran (2MeTHF) with a minimal fraction of dimethyl sulfoxide (DMSO), enables rapid crystallisation under mild thermal conditions following deposition, ensuring compatibility with both rigid and flexible substrates. This approach delivers uniform, defect-free perovskite films across large areas, validated through multi-scale characterisation techniques. Leveraging this SRT ink, we fabricate monolithically interconnected mini-modules (active area: 11.5 cm²) using a laser-based P1–P4 scribing process, achieving power conversion efficiencies (PCEs) exceeding 18%, among the highest reported for green, scalable perovskite processing. Performance gains are further enhanced by integrating bar-coated self-assembled monolayers (SAMs) as hole transport layers (HTLs), demonstrating industrial viability without compromising efficiency. Beyond device metrics, this work establishes a new sustainability benchmark by eliminating hazardous solvents and aligning with green chemistry principles, including low toxicity, biodegradability, and reduced environmental persistence. Our findings represent a critical step toward high-throughput, eco-friendly fabrication of perovskite solar modules, bridging the gap between laboratory innovation and industrial deployment.
[Display omitted]
•Solvent system with significantly reduced toxicity for perovskite inks compatible with bar and slot-die coating routes.•Bar-coated SAM HTLs enable efficient, interlayer-free p–i–n mini-modules.•Perovskite solar mini-modules, with the active area of 11.5 cm² reach 18.2% efficiency.•GIWAXS reveals textured tetragonal MAPbI₃ with minimal secondary phases.•Large-grain, smooth perovskite films show excellent PL and TRPL uniformity.
