Issue 5, 2020

Light extraction from quantum dot light emitting diodes by multiscale nanostructures

Abstract

Improving the light extraction efficiency by introducing optical–functional structures outside of quantum dot light emitting diodes (QLEDs) for further enhancing the external quantum efficiency (EQE) is essential for their application in display and lighting industries. Although the efficiency of QLEDs has been optimized by controlling the synthesis of the quantum dots, the low outcoupling efficiency is indeed unresolved because of total internal reflections, waveguides and metal surface absorptions within the device. Here, we utilize multiscale nanostructures attached to the outer surface of the glass substrate to extract the trapped light from the emitting layers of QLEDs. The result indicates that both the EQE and luminance are improved from 12.29% to 17.94% and 122 400 cd m−2 to 178 700 cd m−2, respectively. The maximum EQE and current efficiency improve to 21.3% and 88.3 cd A−1, respectively, which are the best performances among reported green QLEDs with light outcoupling nanostructures. The improved performance is ascribed to the elimination of total internal reflection by multiscale nanostructures attached to the outer surface of the QLEDs. Additionally, the simulation results of the finite-difference time domain (FDTD) also demonstrate that the light trapping effect is reduced by the multiscale nanostructures. The design of novel light outcoupling nanostructures for further improving the efficiency of QLEDs can promote their application in display and lighting industries.

Graphical abstract: Light extraction from quantum dot light emitting diodes by multiscale nanostructures

Supplementary files

Article information

Article type
Paper
Submitted
23 Feb 2020
Accepted
19 Mär 2020
First published
25 Mär 2020
This article is Open Access
Creative Commons BY-NC license

Nanoscale Adv., 2020,2, 1967-1972

Light extraction from quantum dot light emitting diodes by multiscale nanostructures

S. Wang, C. Li, Y. Xiang, H. Qi, Y. Fang, A. Wang, H. Shen and Z. Du, Nanoscale Adv., 2020, 2, 1967 DOI: 10.1039/D0NA00150C

This article is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported Licence. You can use material from this article in other publications, without requesting further permission from the RSC, provided that the correct acknowledgement is given and it is not used for commercial purposes.

To request permission to reproduce material from this article in a commercial publication, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party commercial publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements