Active electrochemical high-contrast gratings as on/off switchable and color tunable pixels

To be viable for display applications, active structural colors must be electrically tunable, on/off switchable, and reversible. Independently controlling the first two functions, however, is difficult because of causality that ties the real and imaginary parts of the optical constants or changing overlap of fields during structural variations. Here, we demonstrate an active reflective color pixel that encompasses separate mechanisms to achieve both functions reversibly by electrochemically depositing and dissolving Cu inside the dielectric grating slits on a Pt electrode with Delta V < 3 V. Varying the modal interference via Cu occupancy in the slits changes the CIE space coverage by up to similar to 72% under cross-polarized imaging. In the same pixel, depolarization and absorption by the dissolving porous Cu switches the color off with a maximum contrast of similar to 97%. Exploiting these results, we demonstrate an active color-switching display and individually addressable on/off pixel matrix that highlights their potential in reflective display applications.

Automated summary

Researchers have developed an active structural color technology for display applications. By electrochemically depositing and dissolving copper on a platinum electrode, they were able to achieve reversible color switching and control. The modulation of copper occupancy in the slits allowed for changes in color interference, highlighting the potential of this technology for reflective display applications.