Issue 5, 2022

Photon-upconverters for blue organic light-emitting diodes: a low-cost, sky-blue example

Abstract

In the research ecosystem's quest towards having deployable organic light-emitting diodes with higher-energy emission (e.g., blue light), we advocate focusing on fluorescent emitters, due to their relative stability and colour purity, and developing design strategies to significantly improve their efficiencies. We propose that all triplet–triplet annihilation upconversion (TTA-UC) emitters would make good candidates for triplet fusion-enhanced OLEDs (“FuLEDs”), due to the energetically uphill nature of the photophysical process, and their common requirements. We demonstrate this with the low-cost sky-blue 1,3-diphenylisobenzofuran (DPBF). Having satisfied the criteria for TTA-UC, we show DPBF as a photon upconverter (Ith 92 mW cm−2), and henceforth demonstrate it as a bright emitter for FuLEDs. Notably, the devices achieved 6.5% external quantum efficiency (above the ∼5% threshold without triplet contribution), and triplet-exciton-fusion-generated fluorescence contributes up to 44% of the electroluminescence, as shown by transient measurements. Here, triplet fusion translates to a quantum yield (ΦTTA-UC) of 19%, at an electrical excitation of ∼0.01 mW cm−2. The enhancement is meaningful for commercial blue OLED displays. We also found DPBF to have decent hole mobilities of ∼0.08 cm2 V−1 s−1. This additional finding can lead to DPBF being used in other capacities in various printable electronics.

Graphical abstract: Photon-upconverters for blue organic light-emitting diodes: a low-cost, sky-blue example

Supplementary files

Article information

Article type
Communication
Submitted
12 noy 2021
Accepted
21 yan 2022
First published
24 yan 2022
This article is Open Access
Creative Commons BY-NC license

Nanoscale Adv., 2022,4, 1318-1323

Photon-upconverters for blue organic light-emitting diodes: a low-cost, sky-blue example

L. Yang, X. W. Chua, Z. Yang, X. Ding, Y. Yu, A. Suwardi, M. Zhao, K. L. Ke, B. Ehrler and D. Di, Nanoscale Adv., 2022, 4, 1318 DOI: 10.1039/D1NA00803J

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