Perovskite solar cells rely on a uniform, defect-free perovskite layer to achieve high performance. The quality of the perovskite film is heavily influenced by the purity, stoichiometry, and phase stability of the precursor solutions. Without a robust methodology, innovation efforts risk failure due to inconsistent material quality, scalability challenges, and environmental concerns. DYE has successfully scaled up the production of high-purity perovskite precursors with adequate batch-to-batch reproducibility for the tandem cell developments in the project.