Surface mediated ligands addressing bottleneck of room-temperature synthesized inorganic perovskite nanocrystals toward efficient light-emitting diodes

Jinfei Dai, Jun Xi*, Yanqing Zu, Lu Li, Jie Xu, Yifei Shi, Xiaoyun Liu, Qinhua Fan, Junjie Zhang, ShuangPeng Wang, Fang Yuan, Hua Dong, Bo Jiao, Xun Hou, Zhaoxin Wu*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

14 Citations (Scopus)

Abstract

Cesium lead halide perovskites (CsPbX3) have become superior candidates for perspective optoelectronic applications. However, room temperature synthesized CsPbX3 nanocrystals (NCs) suffer from serious lattice/surface traps, mostly induced by nonequilibrium reactions and polar solvent systems. Thus, direct assembly of such poor crystals cannot be available toward high efficiency light emitting diodes (LEDs). To address this issue, differing from the general post-treatment works, here we propose a double-terminal diamine bromide salt to in situ passivate the surface traps of room temperature synthesized CsPbBr3 NCs. High-quality NC solutions with photoluminescence quantum yield (PLQY) beyond 90% are obtained owing to the renovated surface bromide vacancies. Meanwhile, instead of longer oleylamine (OLA) ligand, the abridged diamine bromine ligand could significantly enhance charge transport throughout the NC film. In addition, the NC based LED performance is found related to chain length of the ligand, where the optimal luminance of 14021 Cd m(-2) and current efficiency of 25.5 Cd A(-1) are achieved by 1, 4-butanediamine bromide passivated NC devices. This work provides a direct efficient approach to meet the device application of room temperature synthesized perovskite NCs, underlines the significance of selective ligands to address the challenges of NC emitters in future displays and solid-state lighting.

Original languageEnglish
Article number104467
Number of pages7
JournalNano energy
Volume70
DOIs
Publication statusPublished - Apr-2020

Keywords

  • CsPbBr3
  • Double-terminal ligand
  • Nanocrystals
  • Defect passivation
  • Light-emitting diodes
  • PHOTOLUMINESCENCE QUANTUM YIELD
  • CSPBBR3 NANOCRYSTALS
  • CSPBX3 X
  • EMISSION
  • STABILITY
  • EXCHANGE
  • BR
  • LUMINESCENCE
  • HALIDES
  • SHAPE

Cite this