Blade-Coated Solar Minimodules of Homogeneous Perovskite Films Achieved by an Air Knife Design and a Machine Learning-Based Optimization

Perovskite solar technology stands on three different pillars: efficiency, stability, and processability. Focusing on processability, the field demands the achievement of optoelectronic grade active layers with high uniformity fabricated by industry-compatible methods. Herein, the design and implementation of an air knife on a blade coating deposition system, which allows controlling the evaporation rate of the solvents improving the crystallization and uniformity of perovskite films in a p-i-n device are reported. The effect of doctor blade operational parameters is studied using image analysis combined with a machine learning method to identify the most relevant processing variables leading to a uniform perovskite layer with optimal thickness. After implementing the air knife system and finding the best processing conditions, a special perovskite solar minimodule enabling the evaluation of single inner subcells is fabricated. These perovskite subcells reach an average efficiency of 10.1% and remarkably all the subcells deviate less than 20% from this value over a large-area substrate. These results demonstrate the promising potential of this fabrication method for low cost and high deposition rate photovoltaic devices, which is on the path to mass production.

Automated summary

Perovskite solar technology is focused on efficiency, stability, and processability. This study presents a method using an air knife to control solvent evaporation rate in the deposition system, resulting in perovskite films with high uniformity and crystallization. By analyzing images and using machine learning, the optimal processing conditions for achieving uniform perovskite layers are determined. The fabricated perovskite solar minimodule demonstrates high efficiency and stability, indicating the potential for mass production.