Industrially Compatible Fabrication Process of Perovskite-Based Mini-Modules Coupling Sequential Slot-Die Coating and Chemical Bath Deposition

To upscale the emerging perovskite photovoltaic technology to larger-size modules, industrially relevant deposition techniques need to be developed. In this work, the deposition of tin oxide used as an electron extraction layer is established using chemical bath deposition (CBD), a low-cost and solution-based fabrication process. Applying this simple low-temperature deposition method, highly homogeneous SnO2 films are obtained in a reproducible manner. Moreover, the perovskite layer is prepared by sequentially slot-die coating on top of the n-type contact. The symbiosis of these two industrially relevant deposition techniques allows for the growth of high-quality dense perovskite layers with large grains. The uniformity of the perovskite film is further confirmed by scanning electron microscopy (SEM)/scanning transmission electron microscopy (STEM) analysis coupled with energy dispersive X-ray spectroscopy (EDX) and cathodoluminescence measurements allowing us to probe the elemental composition at the nanoscale. Perovskite solar cells fabricated from CBD SnO2 and slot-die-coated perovskite show power conversion efficiencies up to 19.2%. Furthermore, mini-modules with an aperture area of 40 cm(2) demonstrate efficiencies of 17% (18.1% on active area).

Automated summary

In this study, industrially relevant deposition techniques are developed for the fabrication of perovskite photovoltaic cells. The use of chemical bath deposition for tin oxide deposition and slot-die coating for perovskite layer allows for the growth of high-quality and uniform perovskite layers, resulting in improved power conversion efficiencies.