Solution-processed polymer organic light-emitting diodes (OLEDs) doped with triplet-triplet annihilation (TTA)-upconversion molecules, including 9,10-diphenylanthracene, perylene, rubrene and TIPS-pentacene, are reported. The fraction of triplet-generated electroluminescence approaches the theoretical limit. Record-high efficiencies in solution-processed OLEDs based on these materials are achieved. Unprecedented solid-state TTA-upconversion quantum yield of 23% (TTA-upconversion reaction efficiency of 70%) at electrical excitation well below one-sun equivalent is observed.
Keywords: molecularly doped polymer OLEDs; singlet exciton fission; solid-state TTA upconversion; solution-processing; triplet exciton fusion.
© 2017 The Authors. Published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.