Daniel O. Baumann

Fully scalable fabrication routes are one cornerstone required for commercial deployment of monolithic perovskite/silicon tandem solar cells. However, to date industrially viable deposition processes delivering high performance, uniform thin films, and compatibility with established silicon manufacturing remain limited. Here, we present a fully scalable deposition strategy for the entire perovskite top‑cell, including a dip‐coated self‑assembled monolayer hole‑transport layer, a hybrid two‐step inkjet‐printed wide‐bandgap perovskite absorber, and a dip‐coated interfacial passivation. The process shows excellent reproducibility and high device performance. When integrated with textured silicon bottom cells, the tandem solar cells achieve power conversion efficiencies exceeding 30%, highlighting the technological potential of this fabrication route. Scaling the perovskite active area by a factor of >120 results in a single‐junction module with an area of 12.96 cm ² and an efficiency of 17.8%, corresponding to a loss of only 0.53% _abs. per decade of area scaling. This highlights that our process not only delivers high performance tandem devices, but also offers excellent prospects for upscaling the device area. Extensive material analysis and device analysis substantiate the scalability, film quality, and interfacial control achieved. Importantly, this work provides the first demonstration of perovskite/silicon tandem solar cells surpassing 30% efficiency using an inkjet‑printing‐based perovskite absorber deposition.

Vapor phase deposition processes hold great potential for industrializing the deposition of perovskite-based absorbers, offering a pathway to commercialization.

Large‐scale fabrication and optimization of high‐quality polycrystalline perovskite thin films present significant challenges in scientific research and industry. Shifting from single‐spot measurements to imaging techniques facilitates the transition from laboratory‐scale to large‐scale processing. While single‐spot photoluminescence (PL) methods provide high‐depth insights into local optoelectronic characteristics, they are insufficient for assessing reliable information on homogeneity and spatial characteristics. Currently, no PL‐based imaging method delivers a comparable level of information depth on charge carrier dynamics to single‐spot PL methods. In response, this work introduces a non‐invasive imaging technique based on double‐pulse excitation. Varying the time delay between the pulses gives rise to spatial information on relative photoluminescence quantum yield (rPLQY) in thin films, yielding fundamental optoelectronic characteristics such as external radiative and effective non‐radiative recombination rates and charge‐carrier lifetime. Compared to traditional PL‐imaging and k‐imaging demonstrates the superiority of rPLQY‐imaging in revealing charge carrier dynamics. This technique proves applicable across various sample configurations, irrespective of the presence of electrodes and charge transport layers. In addition, the method can estimate surface recombination velocity and variations in escape and parasitic absorption probabilities. Overall, the rPLQY‐imaging method emerges as a valuable tool for scientific research aimed at characterizing and optimizing large‐area perovskite thin films.

Enhancing reproducibility, repeatability, as well as facilitating transferability between laboratories will accelerate the progress in many material domains, wherein perovskite-based optoelectronics are a prime use case. This study presents fully automated perovskite thin film processing using a commercial spin-coating robot in an inert atmosphere. We successfully apply this novel processing method to antisolvent quenching. This process is typically difficult to reproduce and transfer and is now enhanced to exceptional repeatability in comparison to manual processing. Champion perovskite solar cells demonstrate power conversion efficiencies as high as 19.9%, proving the transferability of established manual spin-coating processes to automatic setups. Comparison with human experts reveals that the performance is already on par, while automated processing yields improved homogeneity across the substrate surface. This work demonstrates that fully automated perovskite thin film processing improves repeatability. Such systems bear the potential to become a foundation for autonomous optimization and greatly improve transferability between laboratories.