Solvent engineering in inkjet-printed perovskite solar cells

Inkjet printing is a sterling technique in the fabrication of large-scale perovskite solar cells (PSCs). Whereas, to obtain high quality perovskite films remains challenging because of the control of the drying of droplets. In this work, FAI is totally dissolved in n-Butanol and isopropanol (IPA) to react with PbI 2 /CsBr films. The addition of n-Butanol prolongs the drying time and inhibits the contact line pinning. Accordingly, the inkjet-printed Cs x FA 1-x Pb(I y Br 1-y ) 3 perovskite films show great uniformity with large grain size. We ultimately achieve a champion device with a power conversion efficiency (PCE) of 18.26 % (0.15 cm 2 ).