Tin‐based perovskite light‐emitting diodes: Progress and perspective

Abstract Lead‐based perovskites exhibit exceptional optoelectronic properties, making them highly suitable for light‐emitting diodes (LEDs). However, their intrinsic toxicity, primarily arising from soluble Pb 2+ ions, poses significant environmental and regulatory barriers to large‐scale commercialization. Tin‐based perovskites have emerged as the most promising lead‐free alternatives, retaining favorable charge transport properties and tunable bandgaps while substantially reducing ecotoxicological and human health risks. Nevertheless, the external quantum efficiency (EQE) of tin‐based perovskite LEDs (PeLEDs) remains capped at ∼20%, reflecting a pronounced performance gap relative to state‐of‐the‐art lead‐based counterparts. In this review, we systematically summarize the fundamental structural motifs and photophysical behavior of tin‐based perovskites to identify the root causes limiting film quality, particularly Sn 2+ oxidation under ambient conditions and uncontrolled crystallization kinetics during film formation. We then outline recent device‐level advances, including rational ligand engineering, interfacial dipole modulation, and compositional grading that have enabled measurable EQE improvements. Moreover, we evaluate the practical viability of tin‐based emitters in next‐generation optoelectronic applications, with an emphasis on narrowband pure‐red displays and near‐infrared optical communication. Finally, we highlight three persistent mechanistic challenges: (i) severe nonradiative recombination and imbalanced charge injection stemming from facile Sn 2+ oxidation and inherent p ‐type self‐doping; (ii) pronounced efficiency roll‐off at elevated current densities driven by Auger recombination and localized Joule heating; and (iii) intrinsic operational instability under continuous optoelectronic and thermal stress. We conclude by proposing a unified research framework that integrates rational materials design, machine learning‐guided high‐throughput screening, and scalable fabrication paradigms to guide the development of tin‐based PeLEDs. This roadmap aims to achieve efficiencies and operational robustness comparable to lead‐based devices, thereby enabling truly sustainable high‐performance optoelectronics.