Figure 5.

Time-resolved emission spectra of the doped 4CzIPN:zeonex films at room temperature. (a, b) The prompt and delayed emission of the 0.3 wt % doped film, which is dominated by monomer emission in a nonpolar environment (onset 2.78 eV [446 nm]). (c, d) The 1 wt % film has a small red shift at intermediate times of 50–100 ns because of the dimeric species and returns to full monomer TADF at longer times. (e, f) The 10 wt % film is dominated by the dimer emission but has contributions from the monomer species at prompt and long times, a result of the slower rISC rate for the CT_M in a nonpolar environment. The filled yellow peak overlaid in each panel is the dimer emission observed after a 11 ns delay time from a 10 wt % zeonex film of 4CzIPN at RT using 532 nm excitation (as shown in Figure 4a).