Bridging the Efficiency Gap: Fully Bridged Dinuclear Cu(I)‐Complexes for Singlet Harvesting in High‐Efficiency OLEDs

Abstract

The substitution of rare metals such as iridium and platinum in light-emitting materials is a key step to enable low-cost mass-production of organic light-emitting diodes (OLEDs). Here, it is demonstrated that using a solution-processed, fully bridged dinuclear Cu(I)-complex can yield very high efficiencies. An optimized device gives a maximum external quantum efficiency of 23 ± 1% (73 ± 2 cd A(-1) ).

Review of organic light-emitting diodes with thermally activated delayed fluorescence emitters for energy-efficient sustainable light sources and displays

“…The same is also true for polymeric TADF emitters, where the HOMO and LUMO are located on different monomers of the polymer strand. 75 Both organic 66,78,79 and metal-organic TADF emitters 77 have been shown to reach the maximum theoretical OLED efficiency, which is in the order of 20% to 25% external quantum efficiency in cases where no light-extraction technology is applied. 13 For clarity, the molecular structures of metal-organic TADF emitters are not discussed here.…”

X-ray absorption spectroscopy: towards more reliable models in material sciences

“…The data has been published before. [5] Light grey marks the so-called X-ray absorbtion near edge structure (XANES) region, while the dark grey part of the spectrum is known as extended X-ray absorbtion fine structure (EXAFS). The arrow marks a trace impurity of zinc.…”

“…[17,56,57] Recently, we demonstrated an OLED device with an internal quantum efficiency close to 100%, which puts these materials on par with state-of-the-art iridium emitters. [5] Figure 7. NHetPHOS-complexes [9] As it has been found for other copper emitters, NHetPHOS complexes show photophysical differences when being processed, [21] which raises the question whether the structure is retained when processing the crystalline powders.…”

“…[1,2] With the most recent breakthroughs, copper emitters emitting via a thermally-activated delayed fluorescence (TADF) mechanism [3,4] are now on par with the most efficient state-of-the-art phosphorescent iridium emitters. [5][6][7] However, it has been becoming increasingly apparent that the chemical differences between copper and iridium compounds require special care regarding the determination of the molecular structure. As a standard procedure, many laboratories rely on single crystal X-ray diffraction to determine the structure of copper or iridium-containing molecules.…”

Effects of an Ultra-thin Green Phosphor on White Organic Light-emitting Devices With Double Doped Emissive Layers

“…To realize white emission, one method is by combining red, green and blue three-color emitting materials [1][2][3] and another way is by _______________________ Na Wang, Sichuan Electromechanical Institute of Vocation and Technology, Panzhihua, Sichuan, China combining yellow and blue two-color emitting materials [4][5][6]. For the emitting materials, phosphorescent materials that contain heavy metal such as Ir, Pt, Au, Cu [7][8][9][10][11] can use both 25% singlet and 75% triplet excitons and reach 100% internal quantum efficiency, as a result of the heavy metal effect. Therefore, phosphorescent OLEDs are able to achieve very high device efficiency, and great studies have been focused on phosphorescent white OLEDs.…”