Fabrication of a Solution-Processed White Light Emitting Diode Containing a Single Dimeric Copper(I) Emitter Featuring Combined TADF and Phosphorescence

Micromachines (Basel). 2021 Nov 30;12(12):1500. doi: 10.3390/mi12121500.

Abstract

Luminescent copper(I) complexes showing thermally activated delayed fluorescence (TADF) have developed to attractive emitter materials for organic light emitting diodes (OLEDs). Here, we study the brightly luminescent dimer Cu2Cl2(P∩N)2 (P∩N = diphenylphosphanyl-6-methyl-pyridine), which shows both TADF and phosphorescence at ambient temperature. A solution-processed OLED with a device structure ITO/PEDOT:PSS/PYD2: Cu2Cl2(P∩N)2/DPEPO (10 nm)/TPBi (40 nm)/LiF (1.2 nm)/Al (100 nm) shows warm white emission with moderate external quantum efficiency (EQE). Methods for EQE increase strategies are discussed.

Keywords: P∩N phosphine ligands; combined singlet and triplet harvesting; combined thermally activated delayed fluorescence and phosphorescence; dimeric copper(I) complexes; organic light emitting diodes (OLEDs); thermally activated delayed fluorescence (TADF); white emission; white light emitting OLED (WOLED).