Enhancing the stability of perovskite light-emitting diodes based on Cl-MXene

Abstract

Perovskite light-emitting diodes (PeLEDs) have achieved remarkable breakthroughs in efficiency; however, their insufficient operational stability remains a critical bottleneck hindering commercialization. This issue primarily stems from the inherent disorder during perovskite film formation, which leads to inhomogeneous grain growth and accumulation of interfacial defects, thereby accelerating device degradation. In this work, we innovatively introduce a two-dimensional MXene material (Ti₃C₂Cl₂) as a buried interfacial layer. The surface termination (Cl) functional groups of Ti₃C₂Cl₂ strongly interact electrostatically with Pb²⁺ ions in the perovskite precursor, providing abundant active nucleation sites. This interaction significantly enhances the crystal quality of the perovskite film and effectively suppresses defect density and ion migration. Moreover, the high electrical conductivity of MXene optimizes hole injection and carrier-transporting, promoting balanced charge distribution at the interface and thereby improving the electrochemical stability of the device. Experimental results demonstrate that this interfacial engineering strategy enables PeLEDs to achieve a maximum external quantum efficiency (EQE) of 13.58%, accompanied by a substantially extended T₅₀ operational lifetime. This study confirms the exceptional performance of MXene as an interfacial material and offers a novel pathway toward high-stability, long-lifetime perovskite optoelectronic devices by synergistically enhancing perovskite crystallinity, passivating interfacial defects, and weakening the ion migration effect.