Saule's printed perovskite and the 25.5% measured by Fraunhofer

The publication attributes to Poland's Saule Technologies the development of printed perovskite cells and reports that an independent test by Germany's Fraunhofer ISE measured 25.5% efficiency under cold white LED lighting of 1,000 lux, a level common in offices.

What does not appear is the supplier's contracted revenue and for how long. The Saule Technologies profile maintained by Perovskite-Info records that control passed to shareholder Columbus Energy, that co-founder Olga Malinkiewicz left the board in May 2025 and that the Wroclaw operation was wound down over the course of 2025, with the company in restructuring.

The consequence concerns continuity of supply. Material integrated into windows, blinds and electronic labels creates dependence on warranty and replacement over a long period. Without a manufacturer in operation, laboratory performance does not convert into an installable asset.

What decides the adoption of perovskite in buildings is the existence of a manufacturer with contracted revenue to honour the warranty.