Fig. 1: Marker pen writing of perovskite films.
a (i, ii) Photo of marker pen and scanning electron microscopy (SEM) image of (iii) its core and (iv) tip. b (i) Photo capturing the process of handwriting MAPbI3 perovskite films on a rigid substrate and (ii, iii) SEM images of the resultant perovskite film. c, d Dynamic light scattering (DLS) particle size analysis in fresh and aged precursor inks before and after using marker pens. e In situ microscopy photographs of nucleation evolution of fresh and aged precursor inks before and after using marker pens. f In-situ microscopy images of writing dynamics. g Schematic diagram of working principle of the MPW method.
