Simultaneous Phase Distribution Reconstruct and Defect Passivation for Efficient Quasi-2D Perovskite Light-Emitting Diodes

Quasi-two-dimensional (Q-2D) Ruddlesden-Popper perovskites have excellent optical performance due to self-assembling multiple quantum well structure. However, Q-2D perovskites usually contain a disordered phase distribution, which results in low emission efficiency. In this work, we introduced the 2-aminohexane ligand into the Q-2D perovskite films, reconstructed the phase distribution of the films. In addition, the defects were passivated after introducing the ligand, resulting in low trap density, so as to obtain high-quality Q-2D perovskite films. With this approach, the Q-2D perovskite light-emitting diodes (PeLEDs) achieved a maximum brightness of 187,869 cd m−2 and a peak external quantum efficiency of 21.6%.