Fluorobenzene, tert-butylcarbazole, tert-butylbenzene, and cyanobenzene are the most frequently used substituents to decorate MR-TADF emitters. These examples are either weak electron-withdrawing and/or electron-donating groups and so their incorporation does not disrupt the MR-TADF character. Diphenylamine (DPA) possesses an intermediate electrondonating ability between carbazole, which allows retention of MR-TADF when it is added to a core, and DMAC, which results in a D-A emitter when it is decorated about a MR-TADF core.