Scheme 5. Order of magnitude of rate constants involved in exciton dynamic processes for TADF emitters. As shown, kRISC becomes the rate-limited step during these processes for tuning the lifetime of the excited state (τTADF). kF, kISC, kIC and kRISC are on the orders of 106 to 108, >107, >106 and 102 to 106 respectively, as summarized by previous reports.7–9,13,15,51–54,56,58,61,64 .
