Copper(I) Complexes for Thermally Activated Delayed Fluorescence: From Photophysical to Device Properties

• Published in: Topics in current chemistry (2016) Vol. 374; no. 3; p. 25
• Main Authors: Leitl, Markus J., Zink, Daniel M., Schinabeck, Alexander, Baumann, Thomas, Volz, Daniel, Yersin, Hartmut
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01.06.2016
• Subjects: Chemistry; Chemistry and Materials Science; Chemistry/Food Science; Coordination Complexes - chemistry; Copper - chemistry; Life Sciences; Luminescence; Materials Science; Molecular Medicine; Photoluminescent Materials and Electroluminescent Devices; Physics; Quantum Theory; Review; Temperature; Thermally activated delayed fluorescence; Emission properties; Emitter; Cu(I); TADF; Fluorescence; Triplet harvesting; OLED; Phosphorescence; Electroluminescence; Copper; Singlet harvesting
• ISSN: 2365-0869; 2364-8961
• DOI: 10.1007/s41061-016-0019-1

Molecules that exhibit thermally activated delayed fluorescence (TADF) represent a very promising emitter class for application in electroluminescent devices since all electrically generated excitons can be transferred into light according to the singlet harvesting mechanism. Cu(I) compounds are an important class of TADF emitters. In this contribution, we want to give a deeper insight into the photophysical properties of this material class and demonstrate how the emission properties depend on molecular and host rigidity. Moreover, we show that with molecular optimization a significant improvement of selected emission properties can be achieved. From the discussed materials, we select one specific dinuclear complex, for which the two Cu(I) centers are four-fold bridged to fabricate an organic light emitting diode (OLED). This device shows the highest efficiency (of 23 % external quantum efficiency) reported so far for OLEDs based on Cu(I) emitters.