Centimeter scale color printing with grayscale lithography

Structural color from artificial structures, due to its environmental friendliness and excellent durability, represents a route for color printing applications. Among various physical mechanisms, the Fabry-Perot (F-P) cavity effect provides a powerful way to generate vivid colors in either the reflection or transmission direction. Most of the previous F-P type color printing works rely on electron beam grayscale lithography, however, with this technique it is challenging to make large-area and low-cost devices. To circumvent this constraint, we propose to fabricate the F-P type color printing device by the laser grayscale lithography process. The F-P cavity consists of two thin silver films as mirrors and a photoresist film with a spatially variant thickness as the spacer layer. By controlling the laser exposure dose pixel by pixel, a centimeter-scale full-color printing device with a spatial resolution up to 5 mu m x 5 mu m is demonstrated. The proposed large area color printing device may have great potential in practical application areas such as color displays, hyperspectral imaging, advanced painting, and so on.