Multifunctional Glycinamide Hydrochloride Interface Bridging Enables Efficient Tin Perovskite Light‐Emitting Diodes

ABSTRACT Recently, tin‐based perovskite light‐emitting diodes (PeLEDs) have received extensive attention owing to their near‐infrared (NIR) emission and environmental friendliness. However, tin perovskite films are prone to rapid Sn 2+ oxidation and uncontrollable crystallization, which usually leads to undesirable device performance. Herein, we propose a multifunctional molecular bridging strategy based on glycinamide hydrochloride (GlyACl) for constructing efficient tin‐based NIR PeLEDs. We demonstrate that the C═O and ‐NH 2 groups in the GlyACl molecule form coordination bonds and hydrogen bonds with perovskite and PEDOT: PSS, respectively, thereby effectively suppressing the oxidation of Sn 2+ , reducing defect density, and regulating the crystallization of tin perovskite films. Moreover, GlyACl‐mediated buried interface modification endows the perovskite layer with an undulant morphology, which is favorable for enhancing light output coupling efficiency. Benefiting from these effects, the performance of FA 0.9 Cs 0.1 SnI 3 NIR PeLEDs is remarkably enhanced, with the maximum EQE rising from 6.32% to 10.80%, and the operational lifetime increasing to 9 times that of the control device. This research underscores the significance of buried interface engineering and establishes a viable route toward efficient tin PeLEDs.