Versatile defect passivation methods for metal halide perovskite materials and their application to light-emitting devices

Seungjin Lee, Da Bin Kim, Jae Choul Yu, Chung Hyeon Jang, Jong Hyun Park, Bo Ram Lee, Myoung Hoon Song

Research output: Contribution to journalReview ArticleOtherpeer-review

21 Citations (Scopus)

Abstract

Metal halide perovskites (MHPs) have emerged as promising emitters because of their excellent optoelectronic properties, including high photoluminescence quantum yields (PLQYs), wide-range color tunability, and high color purity. However, a fundamental limitation of MHPs is their low exciton binding energy, which results in a low radiative recombination rate and the dependence of PLQY on the excitation intensity. Under the operating conditions of light-emitting diodes (LEDs), the injected current densities are typically lower than the trap density, leading to a low actual PLQY. Moreover, the defects not only initiate the decomposition of MHPs caused by extrinsic factors, but also intrinsically stimulate ion migration across the interface and lead to the corrosion of electrodes due to interaction between those electrodes, even under inert conditions. The passivation of defects has proven to be effective for mitigating the effects of defects in MHPs. Herein, the origins and theoretical calculations of the defect tolerance in MHPs and the impact of defects on both the performance and stability of perovskite LEDs are reviewed. The passivation methods and materials for MHP bulk films and nanocrystals are discussed in detail. Based on the currently reported advances, specific requirements and future research directions for display applications are suggested.

Original languageEnglish
Article number1805244
Number of pages17
JournalAdvanced Materials
Volume31
Issue number20
DOIs
Publication statusPublished - May 2019
Externally publishedYes

Keywords

  • defects
  • light-emitting diodes
  • metal halide perovskites
  • passivation

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