The Rise of Colloidal Quantum Well Light‐Emitting Diodes

Abstract Colloidal quantum wells (CQWs) recently become one of the most fascinating optoelectronics and microelectronics materials because of their outstanding properties, including ultranarrow emissions, high photoluminescence quantum efficiencies, and large exciton binding energies. Being a significant CQW application, CQW‐based light‐emitting diode (CQW‐LED) exhibits numerous merits such as extremely high color purity, high device efficiency, solution‐processable preparation, adjustable emission, and excellent compatibility with applied electronics. Herein, the progress of high‐performance CQW‐LEDs is insightfully reviewed, where the innovation of CQW materials as well as the optimization of device engineering are systematically summarized. First, the fundamental concepts in CQW‐LEDs are described, including how to realize CQW emitters, construct CQW‐LED architectures, and understand working mechanisms. Subsequently, various state‐of‐the‐art strategies for developing CQW‐LEDs are highlighted, where material optimizations, charge dynamics (e.g., charge injection, transport, and balance), and exciton behaviors (e.g., exciton generation and recombination) have an important effect on device performances. In the end, current challenges as well as future development opportunities are discussed. This work will present deep insights into achieving high‐performance CQW‐LEDs for next‐generation display, lighting, and optical communication technologies.