The perovskite layer was deposited on a stack made of compact titanium dioxide (C/TiO2) and mesoporous TiO2 (mp-TiO2) in ambient air with a two-step process assisted by air and green anti-solvent quenching. “A manufacturing process must guarantee basic requirements such as low cost, reduced waste, reliability, high throughput, excellent performance and stability of the final product,” the research co-author, Luigi Vesce, told pv magazine. “The procedure is based on a scalable blade-coating process in the air without the need for nitrogen.”
He estimated the cost for manufacturing the module at around €25 per square meter. “There are all the conditions to transfer this technology on a pilot line and then an industrial line,” he further explained. “We are currently using this methodology for several European projects and one of these is aimed at building a photovoltaic plant, which will be a further testbed.”
The module is composed of five series-connected cells with each an area of 2.01 cm² and has an aperture area of 11 cm². “We fabricated each module using a semiautomatic blade-coating machine equipped with a heated moving table, a blade coater, a syringe applicator, and a hot-air knife,” the academics specified. “The process is completely confined inside the machine box with controlled temperature and humidity, without any manual operation except for the substrate loading/unloading.”
The best performing device among those produced in the laboratory showed a power conversion efficiency of 16.1%, an open-circuit voltage of 5.59 V, a short-circuit current of 37 mA, and a fill factor of 72.5%. The module efficiency, the researchers went on to say, is not only higher than that of a similar module built through spin-coating, which achieved a 15.5% efficiency, but also only 6% smaller than that of the single small-area cells.
More details on the panel and the related manufacturing process can be found in the paper Ambient Air Blade-Coating Fabrication of Stable Triple-Cation Perovskite Solar Modules by Green Solvent Quenching, published in RRL Solar.
In March, the University of Rome Tor Vergata in Italy also presented a perovskite solar module with a total active area of 42.8 cm2 and aperture area of 50 cm2. The panel was built with 20%-efficient perovskite cells connected in 14 series and was able to retain 90% of the initial efficiency after 800 h of thermal stress at 85