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

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

钙钛矿发光二极管(PeLEDs)具有优异的光电特性,在显示应用中表现出巨大的发展潜力。红、绿和蓝单色PeLEDs的研究已经取得了突破性的进展,但是三色钙钛矿共同电致发光的研究始终迟滞不前。本研究在不同钙钛矿之间引入具有空穴/电子产生和传输能力的中间连接层(ICL),实现了蓝绿双色和红绿蓝三色发光中心共同电致发光。一方面,ICL可以抑制不同钙钛矿之间的离子交换和能量转移;另一方面,ICL具有电荷产生和输运功能,能够确保不同发光中心获得足够的载流子实现独立发光。进一步改变空穴传输层(NPB)的厚度可以调控蓝绿双色发光中心之间的能量均衡分布,当NPB厚度为40 nm时,器件表现出最大外量子效率(External Quantum Efficiency,EQE)为0.33%。红绿蓝钙钛矿共同电致发光器件的最大EQE达到0.5%。本工作首次报道了红绿蓝三色钙钛矿共同电致发光,并为钙钛矿多色发光中心共同电致发光提供了具有参考性的策略,推动了钙钛矿在显示应用中的发展进程。

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,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.Furthermore,the thickness of the hole transport layer(NPB)is regulated,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,and exhibits the largest External Quantum Efficiency(EQE)of 0.33%.The developed red/green/blue tandem PeLED exhibits the highest EQE of 0.5%.In conclusion,this work provides a reference strategy for the co-electroluminescence of multicolor perovskites,which is expected to promote the development of perovskite in display applications.