Efficient Radiative Enhancement in Perovskite Light‐Emitting Devices through Involving a Novel Sandwich Localized Surface Plasmon Structure
He Shao, Xiufeng Wu, Donglei Zhou, Wenda Chen, Lifang Li, Wen Xu, Lin Xu, Biao Dong, Xue Bai, Hongwei Song
Abstract
Abstract In recent years, CsPbX 3 (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 CsPbX 3 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 Ca 2+ ‐CsPbBr 3 QLEDs, where the diameter and spacing of Au NSs and the interaction distance between the Ca 2+ ‐CsPbBr 3 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 Ca 2+ ‐CsPbBr 3 QD layer is improved from 31.5% to 73.3%. Finally, the luminance of Ca 2+ ‐CsPbBr 3 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 × 10 7 to 6.6 × 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.