Research ArticleELECTRICAL CONDUCTORS

Direct observation of intersystem crossing in a thermally activated delayed fluorescence copper complex in the solid state

See allHide authors and affiliations

Science Advances  01 Jan 2016:
Vol. 2, no. 1, e1500889
DOI: 10.1126/sciadv.1500889
  • Fig. 1 Absorption and emission spectra of [(DPEPhos)Cu(PyrTet)] in neat film.

    The solid line represents neat film. The dashed line shows the emission spectrum of amorphous powder. a.u., arbitrary unit. The chemical structure of [(DPEPhos)Cu(PyrTet)] is shown in the inset.

  • Fig. 2 Microsecond photoluminescence decay dynamics of [(DPEPhos)Cu(PyrTet)] in neat film following excitation at 378 nm, detected at 535 nm (PL maximum).

    The red solid line represents a fit to a biexponential decay with a time component of 7.5 μs (0.57 pre-exponential amplitude) and a component of 16.8 μs (0.43), which gives a weighted average lifetime of 11.5 μs. The IRF is also shown.

  • Fig. 3 Time-resolved photoluminescence of [(DPEPhos)Cu(PyrTet)] on the picosecond time scale.

    (A) Picosecond photoluminescence decay dynamics of [(DPEPhos)Cu(PyrTet)] in neat film (open circles) and dissolved in THF (open triangles) detected at 540 to 600 nm, representing emission from the PL maximum and red side. The solid line represents a fit to a monoexponential decay with a time constant of 27 ps. The IRF is depicted as a dotted line with 2.5 ps FWHM. (B) Normalized time-resolved PL spectra of the neat film in the time windows of 0 to 20 ps (red line) and 40 to 60 ps (green line with symbols) and long-lived PL for times longer than 12 ns (thick black line) derived from the background of the measurement.

  • Fig. 4 Schematic representation of excited-state transitions in [(DPEPhos)Cu(PyrTet)].

    Shown are r, radiative transition (solid arrows); nr, nonradiative transition (oscillatory arrows). After excitation to the excited singlet state (Ia), intersystem crossing to the triplet state occurs (kISC). At sufficient temperature, the excitons are repopulated to the excited singlet state (kRISC), and subsequently thermally activated delayed fluorescence occurs. kS and kT depict the rate constants from the excited singlet or triplet state, respectively.

Supplementary Materials

  • Supplementary material for this article is available at http://advances.sciencemag.org/cgi/content/full/2/1/e1500889/DC1

    Fig. S1. Time-resolved PL spectra at different delay times in the neat film.

    Fig. S2. Broadband transient absorption kinetics in the wavelength region 400 to 800 nm with delay times of 35 and 100 ps after the pump pulse (400 nm) with long-lived background subtraction.

  • Supplementary Materials

    This PDF file includes:

    • Fig. S1. Time-resolved PL spectra at different delay times in the neat film.
    • Fig. S2. Broadband transient absorption kinetics in the wavelength region 400 to 800 nm with delay times of 35 and 100 ps after the pump pulse (400 nm) with long-lived background subtraction.

    Download PDF

    Files in this Data Supplement:

Navigate This Article