One-Step Inkjet Printed Perovskite in Air for Efficient Light Harvesting

Solution-processed metal-halide perovskites have demonstrated immense potential in photovoltaic applications. Inkjet printing is a facile scalable approach to fabricate large-area perovskite solar cells (PSCs) due to its cost-effectiveness and near unity material utilization ratio. However, controlling crystallinity of the perovskite during the inkjet printing remains a challenge. The PSCs deposited by inkjet printing typically have much lower power conversion efficiencies (PCEs) than those by spin-coating. Here, we show that high-quality perovskite films could be inkjet-printed with an innovative vacuum-assisted thermal annealing post-treatment and optimized solvent composition. High-performance PSCs based on printed CH₃NH₃PbI₃ with a PCE of 17.04% for 0.04 cm² (13.27% for 4.0 cm²) and negligible hysteresis (lower than 1.0%) are demonstrated. These efficiencies are much higher than the previously reported ones using inkjet-printing (≤12.3% for 0.04 cm²). The inkjet printing combined with vacuum-assisted thermal annealing could be an effective low-cost approach to fabricate high-performance perovskite optoelectronic thin film devices (including solar cells, lasers, photodetectors, and light-emitting diodes) with high-volume production.