Dynamic Multicolor Display with Wide Color Gamut Enabled by Vanadium Oxide‐Based Fabry–Pérot Electrochromic Nanocavities

Abstract Inorganic electrochromic (EC) devices with vibrant multicolor variations are at the forefront of EC technology and play a crucial role in display applications. Expanding the dynamic color gamut of a single EC device has long been a subject of investigation. Herein, a design is presented that employs vanadium oxide (VO x ) as the EC layer and tungsten (W) as the reflective layer to construct an asymmetric Fabry–Pérot (F–P) nanocavity, enabling wide color gamut EC displays. By leveraging the different thicknesses of VO x , this design allows for a range of color changes from yellow and orange to magenta, purple, blue, cyan, and green through dynamic EC modulation. Notably, a typical single W‐VO x (150 nm) F–P nanocavity demonstrates an impressive modulation range of 110 nm, exceeding the capabilities of existing F–P nanocavities. In‐depth structural analysis reveals that the insertion and extraction of Li + ions significantly influence the microstructure and optical properties of VO x film, allowing for greater refractive index adjustment than WO 3 . This facilitates precise control and expansion of the nanocavity's color range through interference effects. This study provides a new perspective for developing dynamically adjustable wide color gamut EC displays and highlights their potential applications in flexible display technologies.