6533b85dfe1ef96bd12bef0f

RESEARCH PRODUCT

Light-emitting electrochemical cells and solution-processed organic light-emitting diodes using small molecule organic thermally activated delayed fluorescence emitters

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EZ-C thanks the University of St Andrews for support. The authors are grateful to the EPSRC for financial support (grants EP/J01771X and EP/J00916). IDWS is a Royal Society Wolfson Research Merit Award Holder. Two novel charged organic thermally activated delayed fluorescence (TADF) emitters, 1 and 2, have been synthesized. Their TADF behavior is well-supported by the multiexponential decay of their emission (nanosecond and microsecond components) and the oxygen dependence of the photoluminescence quantum yields. Spin-coated electroluminescent devices have been fabricated to make light-emitting electrochemical cells (LEECs) and organic light-emitting diodes (OLEDs). The first example of a non-doped charged small organic molecule LEEC is reported and exhibited an external quantum efficiency (EQE) of 0.39% using 2. With a multilayer architecture, a solution-processed OLED device using neat 2 as the emitting layer gave an EQE of 5.1%, the highest reported to date for a nondoped solution-processed small molecule organic TADF OLED. These promising results open up a new area in light-emitting materials for the development of low-cost TADF LEECs. Publisher PDF Peer reviewed