Additive‐Driven Enhancement of Crystallization: Strategies and Prospects for Boosting Photoluminescence Quantum Yields in Halide Perovskite Films for Light‐Emitting Diodes

Halide perovskite light-emitting diodes (PeLEDs) hold great potential for applications in displays and lighting. To enhance the external quantum efficiency (EQE) of PeLEDs, it is crucial to boost the photoluminescence quantum yield (PLQY) of the perovskite films. The use of additives has emerged as a powerful chemical strategy to control the crystallization process in solution-processed perovskite films. The different types of additives that can be used reflect the various types of chemical interactions with the perovskite materials, influencing their crystallization process in various possible ways. Understanding the relationship between these chemical interactions and their impact on the crystallization process is a key step for designing emitters with improved PLQY and devices with superior EQE. Following the logic chain of additive-perovskite interactions, impacts on crystallization, and subsequent enhancement of PLQY and EQE, this review discusses how additives play a pivotal role in influencing the crystallization process to enhance the PLQY of the perovskite films. Furthermore, this assessment addresses the open challenges and outlines future prospects for the development of PeLEDs.