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Prof. Li Liang’s Team Published Research Findings in Nature Photonics

March 05, 2021      Author:

Recently, the research team led by Prof. Li Liang from School of Environmental Science and Engineering, SJTU published online a collaborative research paper entitled “Suppression of temperature quenching in perovskite nanocrystals for efficient and thermally stable light-emitting diodes” in Nature Photonics. In this paper, Prof. Li’s team reported a strategy to achieve near-zero “thermal quenching” of fluorescence in perovskite nanocrystals from room temperature to 100 through surface passivation on fluoride ion. The LED electroluminescent devices they prepared shows excellent resistance to “thermal quenching”.

 

In recent years, quantum-dot LED electroluminescent devices, as lighting display devices of the next generation, have become the focus of research and industrial application. The efficiency and stability of perovskite quantum-dot electroluminescent LED are the key factors in realizing its large-scale commercial applications. In view of this, Prof. Li’s team adopted a surface passivation strategy and used organic fluoride ions to post-process the perovskite quantum dots, which improved the perovskite quantum dots’ fluorescence resistance to “thermal quenching” and ultimately This will help to broaden the product’s future application in more commercial scenarios.

 

Dr. Liu Mingming and Dr. Wan Qun from School of Environmental Science and Engineering, together with Associate Professor Wang Huamiao from School of Mechanical and Power Engineering, are the co-first authors of the paper. Prof. Brovelli Sergio from the University of Milan-Bicocca and Prof. Li Liang are the co-corresponding authors. This research was supported by the National Key Research and Development Program (no. 2017YFE0127100), the National Natural Science Foundation of China (NSFC 21773155), the Guangdong Province Key Research and Development Project (2019B010924001), the Shanghai Jiao Tong University Scientific and Technological Innovation Funds, and the Shanghai Sailing Plan (19YF1422200).

 

Temperature quenching video: http://sese.sjtu.edu.cn/upload/file/file20210302085323.mp4

 

 

SourceSchool of Environmental Science and Engineering

Translated by: Zhang Yue

Proofread by: Xiao Yangning, Fu Yuhe

 

ABSTRACT:

The thermal quenching of light emission is a critical bottleneck that hampers the real-world application of in both electroluminescent and down-conversion light-emitting diodes. Here, we report CsPbBr3 perovskite nanocrystals with a temperature-independent emission efficiency of near unity and constant decay kinetics up to a temperature of 373 K. This unprecedented regime is obtained by a fluoride post-synthesis treatment that produces fluorine-rich surfaces with a wider energy gap than the inner nanocrystal core, yielding suppressed carrier trapping, improved thermal stability and efficient charge injection. Light-emitting diodes incorporating these fluoride-treated perovskite nanocrystals show a low turn-on voltage and spectrally pure green electroluminescence with an external quantum efficiency as high as 19.3% at 350 cd m−2. Importantly, nearly 80% of the room-temperature external quantum efficiency is preserved at 343 K, in contrast to the dramatic drop commonly observed for standard CsPbBr3 perovskite nanocrystal light-emitting diodes. These results provide a promising pathway for high-performance, practical .