Efficient Dion-Jacobson PeLEDs via additive engineering

In the field of quasi two-dimensional (quasi-2D) perovskite light-emitting diodes (PeLEDs), the performance of Dion-Jacobson (DJ) PeLEDs devices still lags behind due to dispersed phase distribution and poor surface morphology. Herein, based on mixed cation perovskite film of (PHDMA)(Cs0.1FA0.9)4Pb5Br16 (n = 5, PHDMA is 1,4-Phenyldimethylammonium), the passivation agent of 5-AVA is introduced to tune the crystallization process, modulate the phase distribution, improve the surface morphology and boost the current efficiency simultaneously. Finally, a record current efficiency of 68.14 cd/A, a record external quantum efficiency (EQE) of 17.1%, a maximum luminance of 12650 cd/m2 with emission peak position at 529 nm are obtained. This is the highest current efficiency and EQE in 1,4-Phenyldimethylammonium dibromide (PHDMADBr)-based green light DJ PeLEDs to the state of the art.