ABSTRACT Quantum dot‐based color conversion layers (QD‐CCLs) have emerged as key spectral‐engineering platforms for next‐generation optoelectronic systems, enabling precise control of light emission through efficient photon conversion. Owing to their high photoluminescence quantum yield, narrow emission linewidth, and size‐tunable bandgaps, quantum dots (QDs) offer significant advantages over conventional phosphors for lighting and display applications. Beyond material properties, QD‐CCL performance is governed by the interplay between material photophysics, optical design, and structural architecture. This review provides a unified perspective on QD‐CCLs by integrating advances across QD materials (Cd‐based, perovskite, and heavy‐metal‐free systems), device architectures, and mechanically deformable platforms. Particular emphasis is placed on optical management strategies that control photon absorption, reabsorption, and light extraction, as well as structural approaches that enhance conversion efficiency and suppress excitation‐light leakage. Emerging design considerations in flexible and stretchable systems are also discussed, highlighting the coupling between mechanical deformation and optical performance. Beyond conventional lighting and displays, QD‐CCLs are further explored as functional photonic interfaces in applications such as visible light communication and human‐machine interfaces. By bridging materials, optics, and device engineering, this review establishes a design framework for QD‐CCLs and outlines future directions toward multifunctional photonic systems.
