Solution-processable multi-color printing using UV nanoimprint lithography

Recently, coloring based on nanostructure-light interaction has attracted much attention, because it has many advantages over pigment-based conventional coloring in terms of being non-toxic and highly durable in the environment, and providing high resolution. The asymmetric Fabry-Perot (FP) cavity absorber is the most manufacturable structure among coloring structures because it is simply produced and easily tunable. However, it cannot be applied practically because of the lack of a manufacturing technique that enables simultaneous fabrication of multi-color structures with different heights. Here, the fabrication of colored reflective characters based on various asymmetric FP absorbers with micrometer-scale pixel size are reported. Various cavities with different thicknesses are fabricated in a single step using UV imprint lithography and a simple deposition process. UV/visible spectroscopy is used to characterize the fabricated FP resonator. This absorber demonstrates high absorption, close to 90%, resulting in vivid colors with high resolution of 12700 DPI. It can be potentially used in reflective color displays field, functionalized color decorations, and security color patterns area. It is believed that this study would open up new possibilities for high density color printing in practical industry by introducing cost effective nanoimprint lithography technology.