We next acquired temperature-dependent time-resolved PL decays of the TSPO1 doped films using multi-channel scaling (MCS). The decays, which are presented in Figures , show both prompt (PF) and delayed fluorescence (DF) components for both emitters. Whereas the prompt component exhibited negligible temperature dependence, the intensity of the DF decreased significantly with decreasing temperature, behavior that is characteristic of TADF compounds. The lifetimes of both PF and DF were estimated by fitting the decays with a multi-exponential decay fitting (for details of the fitting of the decays see page S4, ESI). The prompt, tp, and delayed, td, lifetimes are tp/td = 6.83 ns/13.72 µs and 5.09 ns/95.91 µs for DIDOBNA-N and MesB-DIDOBNA-N, respectively. Both emitters exhibited high radiative rates in the order of 10 8 s -1 (Table ); however, RISC rates are slow at 3.14 × 10 4 s -1 and 9.81 × 10 3 s -1 , respectively for DIDOBNA-N and MesB-DIDOBNA-N; deep blue D-A DOBNA-containing TADF compounds have been reported to show kRISC on average on the order of 10 6 s -1 . More generally, deep blue MR-TADF compounds rarely show kRISC above 10 4 s -1 . The kRISC for DOBNA was reported to be 1.6 × 10 4 s -1 in 1 wt% PMMA, which is just slightly faster than that of MesB-DIDOBNA-N (9.81 × 10 3 s -1 ).