Perovskite Ink with an Ultrawide Processing Window for Efficient and Scalable Perovskite Solar Cells in Ambient Air.

Perovskite solar cells (PSCs) have attracted tremendous attention because of their rapidly growing efficiency and low cost. However, the efficiency of scalably deposited PSCs, especially spray-coated devices, is still lagging far behind that of spin-coated devices because of the complicated crystallization of coated precursor ink. Here, we show a precursor ink with an ultrawide processing window (more than 40 min) for spray-coating by adjusting the precursor component, which benefits the scalable deposition of perovskite films. Coupled with antisolvent extraction and addition of methylamine chloride to perovskite ink, high-quality perovskite films were achieved with large-scale uniformity. A power conversion efficiency (PCE) of 18.5% for rigid sprayed PSCs and 16.15% for flexible sprayed PSCs were achieved. At the square-centimeter level, sprayed PSCs on rigid and flexible substrates were achieved with PCEs of 15.07 and 13.21%, respectively. The one-step single-pass spraying method for versatility substrates at a deposition rate of 540 m h-1 brings great prospects for commercialization of PSCs.