Ambient Air Blade-Coating Fabrication of Stable Triple-Cation Perovskite Solar Modules by Green Solvent Quenching

Although halide perovskite solar cell (PSC) technology reaches, in few years, efficiencies greater than 25%, the cost-ceffective perspective is achievable only if scalable processes in real manufacturing conditions (i.e., pilot line and/or plant factory) are designed and optimized for the full device stack. Herein, a full semiautomatic scalable process based on the blade-coating technique is demonstrated to fabricate perovskite solar modules in ambient conditions. An efficient and stable triple-cation cesium methylammonium formamidinium (CsMAFA) perovskite is deposited in ambient air with a two-step process assisted by air and green anti-solvent quenching. The developed industry compatible coating process enables the fabrication of several highly reproducible small-area cells on module size substrate with an efficiency exceeding 17% and with high reproducibility. Corresponding reproducible modules (less than 2% variability) with a 90% geometrical fill factor achieve an efficiency larger than 16% and T-80 = 750 h in light-soaking condition at maximum power point and room temperature/ambient after encapsulation. Film deposition properties are assessed by different characterization techniques, namely, scanning electron microscopy, profilometry, UV-vis and photoluminescence (PL) spectroscopy, and PL and electroluminescence imaging. The techniques confirm less defects and local coating variations of the ambient air/bladed devices with respect to the nitrogen air/spinned devices.