Improving the Operational Stability of Near-Infrared Quasi-2D Perovskite Light-Emitting Diodes by Cation Engineering

Although organic metal halide perovskite light-emitting diodes (PeLEDs) have been developed rapidly in recent years, their commercialization and further applications are still hindered by ion migration-induced inferior operational stability. Although the formation of a quasi-2D structure is a well-known solution that can efficiently suppress ion migration, the operation lifetime improvement is still limited. In this study, long-chain phenylbutanammonium is used to replace the commonly used phenethylammonium as the L-site cations. With large steric hindrance, ion migration inside the PeLEDs is effectively suppressed. Consequently, the PeLED with near-infrared emission at 763 nm exhibited an operational lifetime (T₉₀) of up to 5.3 h, which is 53-fold higher than that of the control device. This study demonstrates the feasibility of significant stability improvement using a simple cation engineering strategy for PeLEDs.