Statically Multiple Colors and Dynamically Infrared Emissivity Modulation Compatible Electrochromic Devices via Simple Fabry–Perot Photonic Structures

Abstract

The development of electrochromic devices (ECDs) that can dynamically modulate infrared (IR) emissivity while maintaining a wide color gamut distribution for visible (VIS)‐IR compatible spectral manipulation has been a long‐standing challenge. Current ECDs are limited by simultaneous changes in IR emissivity and VIS colors when subjected to external potential, restricting their potential applications. This work presents, for the first time, VIS–IR compatible ECDs capable of displaying VIS multicolor and dynamically modulating IR emissivity via a Ge/HfO₂ Fabry–Perot cavity structure. The all‐solid‐state VIS‐IR compatible ECD with the structure of ITO/NiO/Ta₂O₅/Li/WO₃/ITO/Ge/HfO₂ achieves not only emissivity modulation of 0.20 at potentials of −2.5 V and +2.5 V in the wavelength range of 2.5–25 µm, but also, due to the presence of Fabry–Perot cavity, the novelty compatible device structure achieves static multicolor modulation, thus decoupling VIS and IR emissivity modulation. Additionally, a flexible VIS‐IR compatible ECD based on polyaniline is also constructed. This novel approach offers a promising possibility for multispectral compatible manipulation, VIS multicolor, and IR signal processing applications.