Reconfigurable structural color generation in multicolor pixels using phase-change materials

We introduce multilayer structures based on phase-change materials for reconfigurable structural color generation. These structures can produce multiple distinct colors within a single pixel. Specifically, we design structures that generate either two or four maximally distinct structural colors. We employ a memetic optimization algorithm coupled with the impedance method to identify the optimal combination of materials and layer thicknesses that maximizes the distinctiveness of the generated colors. We demonstrate that our design approach achieves strong color contrast between the generated colors. To elucidate the physical mechanism underlying the observed strong color contrast, we analyze the optimized design using a Fabry–Pérot cavity model. The proposed multilayer design eliminates the need for subwavelength lithography, making it highly suitable for large-scale applications. Our results could lead to a new class of single-cell multicolor pixels, which retain each color without power consumption, making them particularly appealing for low refresh rate displays.