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<p>Blue perovskite quantum dot light-emitting diodes (QLEDs) are highly attractive for new generation high-definition displays, but their practical deployment is hindered by severe efficiency roll-off at high brightness (&gt;4000 cd m<sup>−</sup>²) while maintaining high color purity (CIEy &lt; 0.1). This roll-off arises mainly from non-radiative losses induced by exposed dangling bonds, strong inter-dot coupling, and low permittivity. To conquer this challenge, we develop a multifunctional molecule passivation strategy utilizing 1-ethyl-3-methylimidazolium hexafluorophosphate (EMIMPF₆). The [PF₆]<sup>−</sup> anions coordinate with lead dangling bonds, cesium sites, and weaken coupling, while [EMIM]⁺ cations suppress bromine-related defects and inhibit Auger recombination, collectively reducing exciton quenching pathways. This treatment increases the photoluminescence quantum yield of QD films from 78% to 92% and enables spectrally high color purity blue emission at 472 nm (CIEy = 0.091). Crucially, the resulting devices deliver a record-high external quantum efficiency (EQE) exceeding 20% at 6441 cd m<sup>−</sup>² and maintain 18.47% EQE at 9587 cd m<sup>−</sup>² with nearly eliminated roll-off, representing the best performance to date for blue perovskite QLEDs (CIEy &lt; 0.1). Moreover, the operational lifetime improves by an order of magnitude compared with previous reports.</p>

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Ultra-Low Efficiency Roll-Off High Color Purity Blue Perovskite Quantum Dot LEDs with Exceeding 20% Efficiency

  • 期刊论文

  • 出版模式：

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  • 发表日期：

    2026年3月16日

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  • Mingyuan Xie,
  • Chenghao Bi,
  • Shibo Wei,
  • Zhentao Jiang,
  • Guo Li,
  • Hangren Li,
  • Yong Zhang,
  • Feng Zhao,
  • Meng-Jiao Li,
  • Hui Lin,
  • Ya-Kun Wang,
  • Liang-Sheng Liao,
  • Silu Tao

摘要

Blue perovskite quantum dot light-emitting diodes (QLEDs) are highly attractive for new generation high-definition displays, but their practical deployment is hindered by severe efficiency roll-off at high brightness (>4000 cd m−²) while maintaining high color purity (CIEy < 0.1). This roll-off arises mainly from non-radiative losses induced by exposed dangling bonds, strong inter-dot coupling, and low permittivity. To conquer this challenge, we develop a multifunctional molecule passivation strategy utilizing 1-ethyl-3-methylimidazolium hexafluorophosphate (EMIMPF₆). The [PF₆]− anions coordinate with lead dangling bonds, cesium sites, and weaken coupling, while [EMIM]⁺ cations suppress bromine-related defects and inhibit Auger recombination, collectively reducing exciton quenching pathways. This treatment increases the photoluminescence quantum yield of QD films from 78% to 92% and enables spectrally high color purity blue emission at 472 nm (CIEy = 0.091). Crucially, the resulting devices deliver a record-high external quantum efficiency (EQE) exceeding 20% at 6441 cd m−² and maintain 18.47% EQE at 9587 cd m−² with nearly eliminated roll-off, representing the best performance to date for blue perovskite QLEDs (CIEy < 0.1). Moreover, the operational lifetime improves by an order of magnitude compared with previous reports.