From this, we conclude that the picosecond intramolecular hopping impacts 𝑘 ((# in the low viscous solution by expanding effective triplet spin distribution in the time scale of the molecular collision. The weakness of TAB as a TTA emitter is its short triplet lifetime. The molecular vibronic motion is effective for the exciton hopping between the equivalent sites, but simultaneously accelerates the nonradiative deactivation. Our future task is to enhance 𝑘 ((# further by designing bulky TTA emitters that lengthen 𝑡 VM++W%WMX , which competes with the vibronic hopping, and to develop TTA emitters with extended triplet lifetime while maintaining the improved 𝑘 ((# .