Enhancing the Performance of Perovskite Light-Emitting Diodes by Humidity Treatment

Zhaohua Zhu; Yan Wu; Yang Li; Zixin Zeng; Sai-Wing Tsang; Zhiqiang Guan; Chun-Sing Lee

doi:10.1021/acsami.1c24561

Enhancing the Performance of Perovskite Light-Emitting Diodes by Humidity Treatment

ACS Appl Mater Interfaces. 2022 May 4;14(17):19774-19784. doi: 10.1021/acsami.1c24561. Epub 2022 Apr 20.

Authors

Zhaohua Zhu^{1

2}, Yan Wu^{1

2}, Yang Li^{1

2}, Zixin Zeng³, Sai-Wing Tsang³, Zhiqiang Guan^{1

2}, Chun-Sing Lee^{1

2}

Affiliations

¹ Center of Super-Diamond and Advanced Films (COSDAF), City University of Hong Kong, Kowloon, Hong Kong SAR 000000, P. R. China.
² Department of Chemistry, City University of Hong Kong, Kowloon, Hong Kong SAR 000000, P. R. China.
³ Department of Material Science and Engineering, City University of Hong Kong, Kowloon, Hong Kong SAR 000000, P. R. China.

PMID: 35443777
DOI: 10.1021/acsami.1c24561

Abstract

While humidity treatment has been employed for enhancing the performance of perovskite solar cells and light-emitting diodes (LEDs), only very limited success has been achieved in quasi-two-dimensional (2D) perovskite LEDs (PeLEDs). Here, for the first time, we demonstrate more than one order of magnitude enhancement of the external quantum efficiency (EQE) and electroluminescence (EL) intensity in blue CsPb(Cl/Br)₃ PeLEDs with an organic cation of 2,2-(ethylenedioxy)bis(ethylammonium) (EDBE). Upon humidity treatment, the crystallinity of the three-dimensional (3D) perovskite phase in the EDBE-based perovskite is improved, contributing to an enhancement of photoluminescence quantum yield (PLQY). This work suggests that elaborately modulating the molecular structure of large cations under humidity treatment can serve as an effective strategy to improve the performance of quasi-2D PeLEDs.

Keywords: blue emission perovskite; crystallinity; humidity treatment; large cation; light-emitting diodes; photoluminescence.