Multifunctional Conjugated Molecular Additives for Highly Efficient Perovskite Light-Emitting Diodes

Chung Hyeon Jang, Ye In Kim, Amit Kumar Harit, Jung Min Ha, Sejeong Park, Young Wook Noh, Ah young Lee, Kyeong Su Kim, Jae Woong Jung, Han Young Woo, Myoung Hoon Song

Research output: Contribution to journalArticlepeer-review

11 Citations (Scopus)

Abstract

Further optimization of perovskite light-emitting diodes (PeLEDs) is impeded by crystal deformation caused by residual stress and defect formation with subsequent non-radiative recombination. Molecular additives for defect passivation are widely studied; however, the majority have insulating properties that hinder charge injection and transport. Herein, highly efficient green-emitting PeLEDs are reported by introducing semiconducting molecular additives (Fl-OEGA and Fl-C8A). Transmission electron microscopy shows that conjugated additives exist primarily at the grain boundaries of perovskite, and Kelvin probe force microscopy confirms that the variation in contact potential difference between grain boundaries and perovskite crystal domains is significantly reduced. The residual tensile stress is reduced by 13% and the activation energy for ion migration increases in the Fl-OEGA-treated perovskite film, compared to those of the film without additives. Compared to insulating 2,2′-(ethylenedioxy)diethylamine (EDEA), the introduction of semiconducting additives prevents a significant reduction in the charge-transport capability. Furthermore, the PeLEDs with Fl-OEGA show a negligible shift in the turn-on voltage and a significantly smaller decrease in the current density with increasing Fl-OEGA compared to the devices with EDEA. Finally, the 3D CsPbBr3–PeLEDs show the highest external quantum efficiency of 21.3% by the incorporation of semiconducting Fl-OEGA as a new multifunctional additive.

Original languageEnglish
Article number2210511
JournalAdvanced Materials
Volume35
Issue number24
DOIs
Publication statusPublished - 2023 Jun 15

Bibliographical note

Funding Information:
C.H.J., Y.I.K., and A.K.H. contributed equally to this work. This work was supported by the National Research Foundation (NRF) of Korea (NRF‐2021R1A2C2010298, NRF‐2020R1A4A1018163, NRF‐2022H1D3A3A01077343, NRF‐2020M3H4A3081793, NRF‐2019R1A6A1A11044070, NRF‐2020M3H4A3081814) by Samsung Research Funding & Incubation Center of Samsung Electronics under Project Number SRFC‐TC2103‐01 and by the Research Project Funded by U‐K Brand (1.220033.01) of UNIST.

Publisher Copyright:
© 2023 Wiley-VCH GmbH.

Keywords

  • conjugated additives
  • defect passivation
  • electrical conductivity
  • perovskite light-emitting diodes
  • stress relaxation

ASJC Scopus subject areas

  • General Materials Science
  • Mechanics of Materials
  • Mechanical Engineering

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