Process Parameter Specification and Control in Solution Processing of Hybrid Perovskite Photovoltaics: From Domain‐Specific Jargon to Evidence‐Based, Unambiguous Description of Experimental Workflows

Abstract Within the last 20 years, hybrid perovskite solar cells (PSCs) have reached remarkable power conversion efficiencies. Further, scalability of hybrid perovskite deposition routines and stability of PSCs have been significantly improved. Yet, a critical roadblock remains: Poor reproducibility largely caused by inconsistent control and reporting of process parameters. Key aspects such as the handling of the perovskite solution, the air jet used for drying, or the process atmosphere are often incompletely specified. In response, this review systematically presents the empirical evidence linking process parameters to the film morphology and the device performance for solution‐based one‐step and two‐step deposition routines of highly efficient PSCs as well as large‐area perovskite modules. To maximize interdisciplinary understanding, the process parameters are standardized within the thin‐film solar cell ontology (TFSCO), structured according to the internal logic of sequential deposition and classified by fundamental mass transfer mechanisms. In a final literature study, the state‐of‐the‐art of parameter reporting is assessed—mirroring to the community where reporting standards can be improved. By using the here‐presented parameter list as a template, perovskite workflows become fully and unambiguously specified—bridging the gap between manual and automated process optimization and fostering data‐driven acceleration via digital twins of perovskite research.