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Ultrahigh-efficiency solution-processed simplified small-molecule organic light-emitting diodes using universal host materials

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Science Advances  28 Oct 2016:
Vol. 2, no. 10, e1601428
DOI: 10.1126/sciadv.1601428
  • Fig. 1 Synthesis routes of 2PTPS, 3PTPS, and 4PTPS.
  • Fig. 2 Electrical and electroluminescent characteristics of solution-processed orange-red, green, and blue phosphorescent OLEDs.

    (A) Architecture of solution-processed phosphorescent OLED devices. (B) Current density versus voltage characteristics of phosphorescent orange-red OLEDs with various electron-transporting host materials. EQEs versus current density characteristics of Bt2Ir(acac)-based orange-red (C), Ir(ppy)3-based green (D), and FIrpic-based blue (E) OLEDs with various electron-transporting host materials. (C to E) (Insets) Left: angular electroluminescence (EL) distributions according to viewing angle; right: photographs of devices and their color emission. (F) EL spectra of solution-processed OLEDs with 2PTPS. a.u., arbitrary units.

  • Fig. 3 Characterizations of solution-processed OLEDs with various electron-transporting host materials.

    Characteristics of (A) capacitance versus voltage and (B) transient EL rising of solution-processed phosphorescent orange-red OLEDs. (C) Schematic illustration of EOD architecture. (D) Electron current density of EODs with various kinds of electron-transporting host materials.

  • Fig. 4 Electrical and electroluminescent characteristics of solution-processed phosphorescent WOLEDs with various kinds of electron-transporting host materials.

    (A) Schematics of WOLED device architecture. Current density versus voltage (B) and EQEs versus current density characteristics (C) of phosphorescent WOLEDs (inset: angular EL distributions according to viewing angle). (D) EL spectra of phosphorescent WOLEDs (inset: optical image of WOLED with 2PTPS). (E) Flexible solution-processed OLED lighting device using 2PTPS on a 5 cm × 5 cm PET substrate.

  • Table 1 Physical properties of electron-transporting host materials.
    HOMO (eV)ΔE (eV)LUMO (eV)ET (eV)
    2PTPS−6.474.06−2.412.82
    3PTPS−6.504.20−2.302.82
    4PTPS−6.554.28−2.272.90
    TPBI−6.403.30−2.702.70
  • Table 2 Device efficiencies of solution-processed OLEDs.
    CEmax (cd/A)EQEmax (%)
    2PTPS
    Orange95.735.4
    Green101.529.0
    Blue38.720.9
    White61.523.1
    3PTPS
    Orange97.535.5
    Green88.523.7
    Blue32.619.6
    White74.228.5
    4PTPS
    Orange76.428.0
    Green
    Blue28.814.3
    White
    TPBI
    Orange60.621.2
    Green79.519.9
    Blue18.610.0
    White40.515.4

Supplementary Materials

  • Supplementary material for this article is available at http://advances.sciencemag.org/cgi/content/full/2/10/e1601428/DC1

    Supplementary Materials and Methods

    table S1. Physical properties of 2PTPS, 3PTPS, and 4PTPS.

    table S2. Work functions with a function of PFI concentration in GraHIL compositions measured by UV photoelectron spectroscopy in air (AC2, Riken Keiki Co. Ltd.).

    table S3. Calculated HOMO, LUMO, ET, and dipole moment.

    fig. S1. CV spectra of 2PTPS, 3PTPS, and 4PTPS.

    fig. S2. UV-vis absorption and photoluminescence of 2PTPS.

    fig. S3. UV-vis absorption and photoluminescence of 3PTPS.

    fig. S4. UV-vis absorption and photoluminescence of 4PTPS.

    fig. S5. Phosphorescence spectra of 2PTPS, 3PTPS, and 4PTPS at 77 K.

    fig. S6. Chemical structure of PFI.

    fig. S7. X-ray photoelectron spectroscopy molecular depth profiles of the GraHIL.

    fig. S8. Angular EL distributions according to viewing angles of solution-processed OLEDs.

    fig. S9. Normalized EL spectra according to viewing angles of solution-processed OLEDs.

    fig. S10. CEs of solution-processed OLEDs.

    fig. S11. Photoluminescence of mixed-host EMLs and UV-vis absorption of phosphorescent dopants.

    fig. S12. Photoluminescence of mixed-host EMLs according to concentration of phosphorescent dopant.

    fig. S13. Capacitance versus voltage characteristics of mixed-host EMLs.

    fig. S14. Current density versus voltage of OLEDs using TCTA/2PTPS EML according to phosphorescent dopants.

    fig. S15. Schematic illustrations of device structure for solution-processed single-carrier devices.

    fig. S16. Current density versus voltage of single-carrier devices according to phosphorescent dopants.

    fig. S17. Negative differential susceptance versus frequency of EODs.

    fig. S18. Calculated electron mobilities of 2PTPS, 3PTPS, 4PTPS, and TPBI.

    fig. S19. Density functional theory calculations of 2PTPS, 3PTPS, and 4PTPS.

  • Supplementary Materials

    This PDF file includes:

    • Supplementary Materials and Methods
    • table S1. Physical properties of 2PTPS, 3PTPS, and 4PTPS.
    • table S2. Work functions with a function of PFI concentration in GraHIL compositions measured by UV photoelectron spectroscopy in air (AC2, Riken Keiki Co. Ltd.).
    • table S3. Calculated HOMO, LUMO, ET, and dipole moment.
    • fig. S1. CV spectra of 2PTPS, 3PTPS, and 4PTPS.
    • fig. S2. UV-vis absorption and photoluminescence of 2PTPS.
    • fig. S3. UV-vis absorption and photoluminescence of 3PTPS.
    • fig. S4. UV-vis absorption and photoluminescence of 4PTPS.
    • fig. S5. Phosphorescence spectra of 2PTPS, 3PTPS, and 4PTPS at 77 K.
    • fig. S6. Chemical structure of PFI.
    • fig. S7. X-ray photoelectron spectroscopy molecular depth profiles of the GraHIL.
    • fig. S8. Angular EL distributions according to viewing angles of solution-processed OLEDs.
    • fig. S9. Normalized EL spectra according to viewing angles of solution-processed OLEDs.
    • fig. S10. CEs of solution-processed OLEDs.
    • fig. S11. Photoluminescence of mixed-host EMLs and UV-vis absorption of phosphorescent dopants.
    • fig. S12. Photoluminescence of mixed-host EMLs according to concentration of phosphorescent dopant.
    • fig. S13. Capacitance versus voltage characteristics of mixed-host EMLs.
    • fig. S14. Current density versus voltage of OLEDs using TCTA/2PTPS EML according to phosphorescent dopants.
    • fig. S15. Schematic illustrations of device structure for solution-processed single-carrier devices.
    • fig. S16. Current density versus voltage of single-carrier devices according to phosphorescent dopants.
    • fig. S17. Negative differential susceptance versus frequency of EODs.
    • fig. S18. Calculated electron mobilities of 2PTPS, 3PTPS, 4PTPS, and TPBI.
    • fig. S19. Density functional theory calculations of 2PTPS, 3PTPS, and 4PTPS.

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