FA cation replenishment-induced second growth of printed MA-free perovskites for efficient solar cells and modules

Printing is one industrially compatible scalable method for the preparation of perovskite thin films but suffers from a low nucleation rate that causes an inferior crystal quality. In this work, we applied a slot-die coating method to deposit a MA-free perovskite thin film with a subsequently introduced FA+ replenishment to induce a second growth and prepare a FA-rich film. As a result, the inverted perovskite mini-module reached an efficiency of 17.56% with an aperture area of 60.84 cm2.