To elucidate the relationship between phosphorescence properties, molecular geometry, and the energetic ordering of triplet states, the ΔCTST% between S1 and T1/T2 and SOC elements between S1/S0 and T1/T2 were calculated (Fig. , Supplementary Fig. ). In the case of BPSF, the T2 exhibits dominate 3 LE character with ΔCTST of 92.6% and acts as an intermediate state that facilitates strong vibronic coupling between LE and 3 CT, and then facilitate the spin flipping process and TADF emission. For TCBPSF (Fig. ), the presence of attached dendrons influences the dihedral angle and alters the characteristics of the triplet states, causing the 3 CT state to shift upwards and This suggests the possibility of the up-converted anti-Kasha dual phosphorescence in a rigid environment. In the case of HCBPSF (Fig. ), the dendrons regulate the dendrimer structures, resulting in a more planarized conjugated configuration that further elevates the energy of CT and lowers the energy of 3 LE state. As a result, the T1 predominantly exhibits the 3 LE state, while T2 represents the CT state with a small SOC (S0, T1) of 3.27 cm -1 . Consequently, T1 becomes highly stable and emits afterglow phosphorescence in a rigid matrix. These findings indicate that the introduction of dendrons effectively modulates the electronic structure of the excited state, leading to different combinations of CT and LE transitions and, subsequently, diverse emission properties.