Triplet–Polaron‐Interaction‐Induced Upconversion from Triplet to Singlet: a Possible Way to Obtain Highly Efficient OLEDs

Two D–A-type molecules, 4-N-[4-(9-phenylcarbazole)]-3,5-bis(4-diphenylamine)phenyl-4H-1,2,4-triazole and 4,4′-(9-(4-(1-phenyl-1H-phenanthro[9,10-d]imidazol-2-yl)phenyl)-9H-carbazole-3,6-diyl) bis-(N,N-diphenylaniline), are designed and synthesized. Organic lightemitting diodes based on them exhibit deep-blue emission and the singlet formation ratios are higher than the simple spin-statistics of 25%. A triplet-polaroninteraction-induced upconversion from triplet to singlet through a one-electron transfer mechanism is proposed, and is proven by magnetocurrent measurement and quantum-chemistry computation. As a service to our authors and readers, this journal provides supporting information supplied by the authors. Such materials are peer reviewed and may be re-organized for online delivery, but are not copy-edited or typeset. Technical support issues arising from supporting information (other than missing files) should be addressed to the authors. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.