Light‐emitting diodes enabled by two‐dimensional semiconductors: Architectures, optimization, and functional advances

Abstract Two‐dimensional (2D) semiconductors offer unique advantages for light‐emitting diodes (LEDs) due to their atomic‐scale thickness, strong excitonic effects, tunable band structures, and compatibility with Van Der Waals heterostructures. These properties enable fine control over carrier injection, exciton recombination, and light–matter interactions, facilitating functionalities not easily achieved in bulk semiconductors. This review provides a comprehensive overview of 2D material‐based LEDs, with emphasis on device architectures, performance modulation, and emerging applications. Key configurations, such as p–n junctions, Schottky contacts, and quantum well heterostructures, are examined in terms of charge transport and emission behavior. Strategies to tailor emission properties are discussed, focusing on band structure engineering, interface optimization, and photonic field control. Additionally, unique electroluminescence phenomena arising from spin–valley coupling, in‐plane anisotropy, and multi‐exciton dynamics are highlighted, enabling polarized, valley‐resolved, and dynamically tunable emission. These capabilities open up opportunities for integration into quantum light sources, neuromorphic vision, and reconfigurable photonic platforms. To advance toward practical applications, improvements are needed in spectral tunability, light‐extraction efficiency, and scalable fabrication. Continued progress in materials synthesis, device engineering, and photonic integration is expected to accelerate the development of high‐performance, application‐oriented 2D optoelectronic systems.