Improving the Stability of Organic–Inorganic Hybrid Perovskite Light-Emitting Diodes Using Doped Electron Transport Materials

Taejun Kim, Jin Hoon Kim, Ross E. Triambulo, Hyowon Han, Cheolmin Park, Jin Woo Park

Research output: Contribution to journalArticlepeer-review

5 Citations (Scopus)

Abstract

Herein, organic–inorganic hybrid perovskite light-emitting diodes (PeLEDs) are fabricated under ambient air and all-solution conditions. A novel N2 gas blowing step is applied during spin-coating of the precursor solution to obtain uniform methylammonium lead bromide (MAPbBr3) perovskite nanocrystal films with fewer surface and interfacial defects than solution-processed perovskite films. Furthermore, polyethylenimine (PEI) and poly[9,9-dioctyl-9′,9′-bis[3-(trimethylammonio)propyl][2,2′-bi-9H-fluorene]-7,7′-diyl] (PFN) are used as doping agents in the widely used electron transport layer (ETL) material, 2,2′,2″-(1,3,5-benzinetriyl)-tris(1-phenyl-1-H-benzimidazole) (TPBi), and act as passivation agents between the rough surface of the perovskite film and the ETL. Consequently, the high surface work function of PEI- and PFN-doped TPBi results in reduced and balanced injection of electrons in the perovskite light-emission layer (EML) of the PeLEDs, producing a maximum luminance (L) up to 14 358 and 11 465 cd m−2 for the PEI- and PFN-based PeLEDs, respectively. The doped-ETL-based PeLEDs also show a 3.6 times longer L50 (i.e., the time needed for a 50% reduction in the initial value of L operated at 4 V) than the pure TPBi-based PeLEDs, which need a separate poly(methyl methacrylate) (PMMA) film to act as the passivation layer between the EML and ETL.

Original languageEnglish
Article number1900426
JournalPhysica Status Solidi (A) Applications and Materials Science
Volume216
Issue number20
DOIs
Publication statusPublished - 2019 Oct 1

Bibliographical note

Funding Information:
This research was supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT & Future Planning (grant number: 2018R1A2B6001390).

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Surfaces and Interfaces
  • Surfaces, Coatings and Films
  • Electrical and Electronic Engineering
  • Materials Chemistry

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