Multipass Inkjet Printing of Lead Halide Perovskite Pixels onto Flexible Substrates

We present a facile method of writing single perovskite pixels onto flexible substrates by inkjet printing of precursor solution. The optimum amount of material per pixel was determined using multipass printing. The surface morphology and surface energy of the substrate were optimized to obtain well-defined pixels with a resolution of 500 dots per inch or higher. MAPbI3 perovskite pixels of sizes as low as 30 μm were printed in 5 × 5 arrays on PET substrates coated with various polymers as well as with mesoporous silica. Among all surface modifications used, the pixels printed on PMMA-coated and mesoporous silica-coated PET substrates showed the best performance with a well-defined circular shape and the highest photoluminescence (PL) intensity. The morphology development and the optical performance of the pixels per printing pass were characterized in detail with confocal fluorescence microscopy, PL measurements, and scanning electron microscopy.