Structural color image augmented by inkjet printed perovskite patterning

Combination of luminescence and diffraction effects is an approach in advanced security printing allowing for development of unique patterns that can be authenticated by two features at once. In this way, all-inorganic halide perovskites with efficient, stable, and spectrally narrow photoluminescence at room temperature could be one of the best candidates for such applications. This work demonstrates a technology, in which structural color images on Volume Bragg Hologram (VBH) and luminescent CsPbBr3 perovskite pattern are applied layer by layer in the form of predesigned patterns using inkjet printing. The structural color image is formed due to the pointwise changing of VBH period with acrylic ink. The perovskite-based luminescent pattern is developed from the precursor ink in situ in the form of distinct drops allowing for the micropatterning. To achieve the goal, the printing conditions were optimized for these two types of inks, using a layer of polystyrene to enhance the luminescence of perovskites. The effect of perovskites on optical properties of the holographic substrate was taken into account. The results show a high potential of the halide perovskites for novel multi-level security printing technologies.