Emergence of Perovskite‐Based Light‐Emitting Electrochemical Cells

Perovskite semiconductors have become pivotal within photonics research thanks to the exceptional optoelectronic properties, such as spectrally narrow emission, tunable energy gap, high photoluminescence efficiency, and facile solution‐treatability. As an emerging electroluminescent device, perovskite‐based light‐emitting electrochemical cell (PeLEC) features simple device architecture, solution processability, and cost‐effective fabrication. In this review, the recent development of PeLECs is comprehensively summarized. At first, the initial section elucidates the fundamental principles of PeLECs, encompassing perovskite material structures, band characteristics, and operational mechanisms of PeLECs. Subsequently, key strategies to achieve PeLECs are analyzed, focusing on material optimization and device improvement. In addition, the extended applications of PeLECs integrating light‐emission and detection functionalities are discussed. In the end, current technical challenges and prospective research directions are assessed. This work will present insightful guidelines to realize highly efficient and stable PeLECs for the new‐generation display, lighting, and related photonics technologies.