Chelating-agent-assisted control of CsPbBr3 quantum well growth enables stable blue perovskite emitters

Ya Kun Wang, Dongxin Ma, Fanglong Yuan, Kamalpreet Singh, Joao M. Pina, Andrew Johnston, Yitong Dong, Chun Zhou, Bin Chen, Bin Sun, Hinako Ebe, James Fan, Meng Jia Sun, Yuan Gao, Zheng Hong Lu, Oleksandr Voznyy, Liang Sheng Liao, Edward H. Sargent*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

112 Scopus citations

Abstract

Metal halide perovskites have emerged as promising candidates for solution-processed blue light-emitting diodes (LEDs). However, halide phase segregation – and the resultant spectral shift – at LED operating voltages hinders their application. Here we report true-blue LEDs employing quasi-two-dimensional cesium lead bromide with a narrow size distribution of quantum wells, achieved through the incorporation of a chelating additive. Ultrafast transient absorption spectroscopy measurements reveal that the chelating agent helps to control the quantum well thickness distribution. Density functional theory calculations show that the chelating molecule destabilizes the lead species on the quantum well surface and that this in turn suppresses the growth of thicker quantum wells. Treatment with γ-aminobutyric acid passivates electronic traps and enables films to withstand 100 °C for 24 h without changes to their emission spectrum. LEDs incorporating γ-aminobutyric acid-treated perovskites exhibit blue emission with Commission Internationale de l'Éclairage coordinates of (0.12, 0.14) at an external quantum efficiency of 6.3%.

Original languageEnglish (US)
Article number3674
JournalNature communications
Volume11
Issue number1
DOIs
StatePublished - Dec 1 2020

ASJC Scopus subject areas

  • General Physics and Astronomy
  • General Chemistry
  • General Biochemistry, Genetics and Molecular Biology

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