Numerical and Analytical Study of Tunable Color Control in Quantum-Dot Top-Emission Light-Emitting Diodes Using a Liquid-Crystal-Assisted Metal-Insulator-Metal Cavity.

Ultrahigh-resolution displays for augmented and virtual reality require compact pixel architectures, but conventional red, green, and blue subpixel layouts increase lateral complexity as the pixel size decreases. Active color tuning within a single emissive unit offers an alternative route, although practical device architectures remain challenging. Here, we report a numerical and analytical study of a quantum-dot light-emitting diode architecture combined with a liquid-crystal-assisted metal-insulator-metal cavity for electrically tunable color control. Reorientation of the embedded liquid-crystal layer changes the effective optical path length of the cavity, which shifts the Fabry-Pérot resonance and thereby reweights the spectral content transmitted from a fixed quantum-dot emission spectrum. The structure was optimized using an analytical plane-wave multilayer model and cross-checked against finite-element-method simulations, with the wavelength dependence of all optical constants retained throughout. The optimized design reached a CIE 1931 chromaticity triangle area of 0.124 in the analytical model and 0.113 in the numerical model and retained an area of 0.121 averaged over a 15° viewing cone. Alternative tuning branches and a quasi-white operating state were also identified. These results suggest that liquid-crystal-assisted metal-insulator-metal cavities may serve as compact, electrically tunable spectral-control elements for high-density display architectures and reconfigurable photonic systems.