Multicolored Displays with Selective Visible‐Infrared Spectral Modulation for Optical Information Transmission

Abstract Polyaniline (PANI) can achieve reversible optical modulation in visible and infrared (IR) bands under the action of voltage. However, PANI‐based electrochromic devices cannot cope with the dual detection of visible and IR light to realize the transmission of information due to the linkage restriction between the spectral modulation in the visible and IR region. Here, IR low‐absorptive inorganic pigments as colorants and IR high‐transparent polymer as a binder are utilized to prepare colored films with high transparency. A camouflage layer against visible light detection is constructed on the surface of IR electrochromic devices, and the information transmission is realized in the IR band by controlling the thermal radiation characteristics. Furthermore, thermochromic microcapsules (TMs) that change color under external thermal stimuli are introduced to fabricate a thermochromic and IR transparent functional layer, which is attached to the surface of IR electrochromic devices and endows the devices with separate spectral modulation ability in the visible and IR region. Multicolored displays are fabricated by arraying various devices. Moreover, visual patterns are prepared on the surface of IR electrochromic devices by dispensing technology. This configuration endows the device with a promising potential for anti‐counterfeiting, optical security, and related applications.