Defect Passivation and Emission Enhancement in Pure‐Red Quasi‐2D Perovskite LEDs via Multifunctional Amide Modulation

Abstract Although extensive research has been devoted to composition modulation of quasi‐2D perovskite light‐emitting diodes (PeLEDs) to enhance electroluminescence, achieving an optimal energy landscape for efficient pure‐red emission remains challenging. This is primarily due to the detrimental aggregation of low‐dimensional phases and defects in the perovskite films, which undermines both device efficiency and operational stability. Herein, a multifunctional molecule, 4‐Amino‐benzeneacetamide (4‐AMINO), is introduced to passivate defects and modulate the growth of quasi‐2D perovskites, thereby reducing nonradiative recombination. Benefiting from the favorable properties of 4‐AMINO‐modified perovskites, pure‐red PeLEDs emitting at 632 nm with a peak external quantum efficiency of 10.2% and a maximum brightness of 1351 cd m −2 are achieved. This work presents an effective approach for realizing high‐performance and stable pure‐red PeLEDs toward practical applications.