Multiple Chemical Interactions in Additive Engineering of Perovskite for Enhanced Efficiency and Stability of Pure Blue Light-Emitting Diodes

Additive engineering is extensively employed in perovskite light-emitting diodes (PeLEDs) to enhance the device performance. However, the effectiveness of additives is restricted, as they generally interact with only one or two components within the perovskite structure. Consequently, these additives are unable to fulfill the comprehensive functional requirements imposed by perovskite light-emitting materials. In this work, we successfully designed and synthesized a multifunctional additive of <i>N</i>-(perfluorophenyl)-<i>P</i>,<i>P</i>-diphenylphosphinic amide (PFNPO) via a one-step synthesis approach. Multiple chemical interactions can be provided between PFNPO and different perovskite components, thereby effectively modulating quasi-two-dimensional (quasi-2D) perovskite crystallization, passivating coordination-unsaturated Pb defects, and suppressing halide ion migration simultaneously. Based on these synergistic effects, the incorporation of PFNPO in pure blue quasi-2D PeLEDs resulted in a significant enhancement in external quantum efficiency from 1.83 to 4.26%, an operational lifetime that was extended by more than 3-fold, and improved spectral stability at 466 nm.