Strategies for Enhancing External Quantum Efficiency in All‐Inorganic Perovskite‐Based Light‐Emitting Diodes

ABSTRACT

Perovskite light‐emitting diodes (PeLEDs) are increasingly recognized as promising candidates for next‐generation display and lighting technologies owing to their exceptional color purity, high luminance, wavelength tunability, and compatibility with low‐cost solution processing. However, despite rapid progress, simultaneously achieving high external quantum efficiency (EQE) and robust operational stability remains a critical barrier to practical deployment and commercialization. This review provides a comprehensive overview of recent strategies to enhance the EQE of all‐inorganic PeLEDs while also highlighting the stability constraints that govern their real‐world applicability. Key approaches discussed include composition engineering, defect passivation, low‐dimensional emitter design, interface optimization, device architecture optimization, and improvements in charge injection, transport, and exciton recombination dynamics. We further clarify the scope of all‐inorganic systems relative to organic‐inorganic hybrid and quasi‐2D perovskites, distinguishing purely inorganic emitters from hybrid comparative systems that employ organic spacer cations. Representative organic molecules used as passivators, additives, and interlayers are discussed in terms of their chemical functions in defect management, energy‐level alignment, morphology control, and exciton utilization. Collectively, these advances define a more balanced framework for evaluating both efficiency and durability in all‐inorganic PeLEDs and for accelerating their technological maturation toward practical use.