Carrier Balanced Distribution Regulation of Multi-emissive Centers in Tandem PeLEDs

Perovskite light-emitting diodes (PeLEDs), owing to their unique photoelectric performance, show promising prospects in display applications.Red, green, and blue monochromatic PeLEDs have achieved remarkable breakthroughs, but the study of red/green/blue perovskite co-electroluminescence is still delayed.This study proposed a strategy that an intermediate connection layer (ICL) with hole/electron generation and transport capability is introduced between perovskites.On the one hand, the introduction of the ICL can inhibit ion exchange and energy transfer.On the other hand, ICL has a charge-generation function that ensures different perovskite centers capture enough carriers.Furthermore, the thickness of the hole transport layer (NPB) is optimized, by which the energy distribution of blue and green dichroic emission centers is regulated.When the thickness of NPB is 40 nm, the blue/green tandem PeLED achieved relatively balanced luminescence and exhibits the largest EQE of 0.33%.The developed red/green/blue tandem PeLED exhibits the highest EQE of 0.5%, which is the first report in the field of PeLEDs.This work provides a reference 第*期 王 润, 等: 钙钛矿多色级联发光二极管中多中心载流子均衡分布调控研究 2 strategy for the co-electroluminescence of multicolor perovskites, and is expected to promote the development of perovskite in display applications.