Fig. 3: Delayed RTP mechanism of carbazole-phosphine hybrids.

a Sliced time-resolved emission spectra (TRES) of DCzSBr, DCzDBr, DCzSBrSP and DCzSBrSPO powders. The corresponding energy transfer processes are highlighted with arrows and insets. For DCzSBr and DCzDBr, only direct energy transfer from the T₁ to T_n^* states can be recognized, corresponding to typical IRTP process; while, for DCzSBrSP and DCzSBrSPO, new phosphorescence bands between their T₁ to T_n^* states are observed and attributed to the T_M states, which transfer triplet energy from the T₁ to T_n^* states. b Emission spectral evolution of DCzSBrSP at four representative stages of 5–10 µs, 100–150 µs, 400–500 µs and 5–10 ms. Sliced TRES profiles of DCzSBr and TPPBr powders are included for comparison. TPPBr with the structure same with phosphine mediate group in DCzSBrSP is used to clarify origin of intermediate energy levels (T_M). The correspondence between the spectra of DCzSBrSP, and DCzSBr and TPPBr are indicated with the same curve colors and dash lines.