Compact Pixel Architectures Enabled by Frequency‐Modulated Color‐Tunable AC‐Driven Electroluminescent Devices

Abstract In this study, a non‐carrier‐injection quantum‐dot based alternating current electroluminescent device based on a novel tandem emission layer architecture, enabling continuous color tunability for a single color of both emission layers and their mixed colors through a frequency modulation strategy is proposed. The key to the device operation lies in the introduction of a charge buffer layer between the emission layers, enabling precise regulation of charge transport between the top and bottom quantum dot layers. The device exhibits fully continuous and directionally controllable color‐tuning capability, with a peak luminance of up to 1200 cd m − 2 and excellent cycling stability. It is revealed that the capacitances of the top and bottom structures of the device are frequency‐dependent, which governs charge distribution and enables frequency‐selective emission. Based on these findings, a full‐color pixel is constructed using two coplanar sub‐pixel units. By integrating a wavelength prediction model, continuously tunable full‐color emission is precisely controlled through voltage/frequency modulation, achieving a color gamut close to the DCI‐P3 standard. This strategy offers a compact device framework and technical pathway for ultra‐high‐resolution displays with reduced complexity and cost.