Modulation of recombination zone position for quasi-two-dimensional blue perovskite light-emitting diodes with efficiency exceeding 5%

Zhenchao Li,Hin-Lap Yip,Yongchao Yang,Yong Cao,Qifan Xue,Ziming Chen

doi:10.1038/s41467-019-09011-5

Zhenchao Li, Hin-Lap Yip + Show 4 more

Open Access

https://doi.org/10.1038/s41467-019-09011-5

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Journal: Nature Communications	Publication Date: Mar 4, 2019
Citations: 443	License type: open-access

Affiliation: South China University of Technology

Abstract

In recent years, substantial progress has been made in developing perovskite light-emitting diodes with near-infrared, red and green emissions and over 20% external quantum efficiency. However, the development of perovskite light-emitting diodes with blue emission remains a great challenge, which retards further development of full-color displays and white-light illumination based on perovskite emissive materials. Here, firstly, through composition and dimensional engineering, we prepare quasi-two-dimensional perovskite thin films with improved blue emission, taking advantages of reduced trap density and enhanced photoluminescence quantum yield. Secondly, we find a vertically non-uniform distribution of perovskite crystals in the PEDOT:PSS/perovskite hybrid film. Through modulating the position of the recombination zone, we activate the majority of quasi-two-dimensional perovskite crystals, and thus demonstrate the most efficient blue perovskite light-emitting diode to date with emission peak at 480 nm, record luminance of 3780 cd m−2 and record external quantum efficiency of 5.7%.

Highlights

In recent years, substantial progress has been made in developing perovskite light-emitting diodes with near-infrared, red and green emissions and over 20% external quantum efficiency
phenylethylammonium bromide (PEABr) is introduced into the CsPbCl0.9Br2.1 perovskite to passivate the trap states and form quasi-2D perovskite, which helps to obtain a blue-emissive quasi-2D perovskite thin film with photoluminescence quantum yield (PLQY) up to 27%
We observe a vertically non-uniform distribution of quasi-2D perovskite crystals in the PEDOT:PSS/perovskite hybrid film in which the majority of perovskite crystals disperse on top of the film and only a few are embedded within the PEDOT:PSS layer

Summary

Introduction

Substantial progress has been made in developing perovskite light-emitting diodes with near-infrared, red and green emissions and over 20% external quantum efficiency.

Results

Conclusion