The feasibility of upscaling the perovskite solar cells technologies to high volume production using roll-to-roll (R2R) slot die coating is demonstrated in this study. Perovskite solar cells are produced by R2R slot die coating on flexible substrates with a width of 30 cm and the web speed of 3–5 m min−1. R2R deposition of the electron transport layer and perovskite is performed at ambient atmosphere from nontoxic solvents compatible with industrial manufacturing. The average stabilized power conversion efficiency of the devices made on different areas of the foil is 12%, with the best value of 13.5%. The demonstrated achievement is an important milestone and a big solid step toward future commercialization of perovskite-based solar cells technologies.@en

Current laboratory-scale fabrication of perovskite solar cells involves the use of toxic solvents in the different fabrication steps. The aim of this research is to find a nontoxic alternative to chlorobenzene used for the deposition of hole transport material (HTM) spiro-OMeTAD. The initial selection of the solvents compatible with industrial manufacturing was performed based on the Hansen solubility model and further verified in a series of solubility tests, because the additives used in the HTM ink, such as lithium bis(trifluoromethanesulfonimidate) (Li-TFSI) and tert-butylpyridine (4-TBP), also have a significant influence on the properties of the final solution. Furthermore, selected solvents were tested on the compatibility with the underlying perovskite layer, which should remain unaffected after the spiro-OMeTAD deposition. A final selection of solvents was tested by the manufacturing of the complete perovskite solar cells. Power conversion efficiency (PCE) and layer quality, as well as possible health issues and environmental concerns, influenced the final selection for future potential industrial processing. The research demonstrated that replacement of chlorobenzene (CB) by p-xylene leads to identical PCEs of the devices, thereby showing that a toxic solvent can be replaced by a nontoxic and industrially compatible one. To prove that the selected solvent is suitable for future large-area coatings, the coatability of the ink was tested in blade-coating deposition. Devices manufactured using blade coating demonstrated identical PCEs to spin-coated devices, which is final proof of the suitability of the selected solvent system.

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The production of electronic devices using solution based (“wet”) deposition technologies has some decisive technical and commercial advantages compared to competing approaches like vacuum based (“dry”) manufacturing. Particularly, the potential to scale up production processes to large areas and high volumes by introducing continuous roll-to-roll (R2R) methods on flexible substrates has been the topic of intense studies from both applied research institutes and industry already for some years. Decisive steps forward have been achieved during that time, resulting in the dawn of commercial applications for a number of processes, while additional development work is still needed in some other fields. This review summarizes the work published during the last few years on the R2R printing and wet coating of electronic devices. An overview is presented of the basic operational principles for the most commonly used R2R printing and coating methods and techniques for proper web handling in R2R lines. Then, the most commonly used types of flexible substrate materials are introduced, followed by a review of the work published in the application areas of transparent conductor materials, printed electric connections, light emitting devices, photovoltaic energy generation, printed logic, and sensing.

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