Performance Optimization and Luminescence Regulation of Quasi-Two-Dimensional Perovskite Light-Emitting Diodes from Red to Orange

Red perovskite light-emitting diodes (RPeLEDs) prepared by quasi-two-dimensional (quasi-2D) perovskites have attracted extensive attention due to their exceptional electroluminescence efficiency and robust device stability. However, current research on the color regulation mechanism of quasi-2D PeLEDs is still not comprehensive. Most researchers have focused on the transformation from green light to blue light, which has hindered the further application and development of quasi-2D PeLEDs in color adjustment. In this paper, we achieve color control from deep red light to orange-yellow light by adjusting the preparation process of quasi-2D films. While improving the color control mechanism of quasi-2D PeLEDs, the preparation method is provided to obtain quasi-2D perovskite structures. We successfully prepared quasi-2D perovskite structures by directly introducing 2D (4-BA)₂PbI₄ (4-BA = 4-benzylaniline) perovskite into the 3D CsPbI₃ perovskite system. RPeLEDs were successfully fabricated by proportional control, additive doping, device structure control, and so on. When the EL of this device is 688 nm, the maximum EQE reaches 7.74%. Subsequently, we optimized the color control of the quasi-2D perovskite device based on this structure by using the halogen doping strategy. A series of quasi-2D RPeLEDs of (4-BA)Cs_0.5PbBr_3.5xI_3.5–3.5x light-emitting layer groups were prepared and successfully realized the luminescence regulation from 684 to 596 nm. The luminous color gradually changed from deep red to orange-yellow. This work provides a special preparation method and improves the color control of quasi-2D PeLEDs in the red-light color gamut, offering valuable references for their development in the display field.