Efficient Radiative Enhancement in Perovskite Light-Emitting Devices through Involving a Novel Sandwich Localized Surface Plasmon Structure

In recent years, CsPbX3 (X = Cl, Br, I) perovskite quantum dots (QDs) have been considered as the most promising materials for light-emitting diodes (LEDs). However, the advances of CsPbX3 quantum dot-based light emitting diodes (QLEDs) still lagged behind inorganic III-V LEDs and other organic LEDs. Herein, a strategy to improve the performances of perovskite QLEDs is reported by utilizing the localized surface plasmon resonance (LSPR) effects of Au nanospheres (NSs). It is accomplished by introducing a Au NS layer into the electron transport layer of Ca2+-CsPbBr3 QLEDs, where the diameter and spacing of Au NSs and the interaction distance between the Ca2+-CsPbBr3 QD and Au NS layers are modulated, according to the theoretical simulation of Finite-difference time-domain. As a result, the photoluminescence quantum yield of Ca2+-CsPbBr3 QD layer is improved from 31.5% to 73.3%. Finally, the luminance of Ca2+-CsPbBr3 QLEDs is improved from 16824 to 63931 cd m(-2) and external quantum efficiency (EQE) is improved from 4.2% to 10.5%. The radiative transition rate can be remarkably modulated from 0.7 x 10(7) to 6.6 x 10(7) s(-1). The enhancement in luminance and EQE are the best values in the LSPR modified perovskite QLEDs and the strategy offered in this work fits with other LEDs and optoelectrical devices.

Automated summary

In recent years, CsPbX3 perovskite quantum dots have been considered as promising materials for LEDs. This study reports a strategy to improve the performance of perovskite QLEDs by utilizing the localized surface plasmon resonance effects of gold nanospheres. The strategy achieves significant improvement in photoluminescence quantum yield, luminance, and external quantum efficiency of the QLEDs.