Sky‐Blue Phosphorescent OLEDs with 34.1% External Quantum Efficiency Using a Low Refractive Index Electron Transporting Layer

Abstract

Blue-phosphorescent organic light-emitting diodes (OLEDs) with 34.1% external quantum efficiency (EQE) and 79.6 lm W(-1) are demonstrated using a hole-transporting layer and electron-transporting layer with low refractive index values. Using optical simulations, it is predicted that outcoupling efficiencies with EQEs > 60% can be achieved if organic layers with a refractive index of 1.5 are used for OLEDs.

Diarylboron‐Based Asymmetric Red‐Emitting Ir(III) Complex for Solution‐Processed Phosphorescent Organic Light‐Emitting Diode with External Quantum Efficiency above 28%

“…Among all the emitting materials developed for OLEDs, phosphorescent transition metal complexes, e.g., Ir(III) and Pt(II) complexes, have drawn great attention due to their capability of harvesting 100% of the both singlet and triplet excitons electrogenerated in devices 6, 7. Using Ir(III) complexes as emitters, blue, green, and orange OLEDs with external quantum efficiencies (EQEs) over 30% have been reported 8, 9, 10, 11, 12. However, even based on elaborately designed bipolar host materials and sophisticated device structures, only several most efficient vacuum‐deposited red OLEDs using Ir(III) complexes as emitters show EQEs around 26% 11, 13, 14, 15, 16.…”

Combining Charge‐Transfer Pathways to Achieve Unique Thermally Activated Delayed Fluorescence Emitters for High‐Performance Solution‐Processed, Non‐doped Blue OLEDs

“…[1][2][3][4][5][6] Utilization of TADF emitters provide an opportunity not only to reduce the overreliance on expensive precious metals for efficient OLEDs, but also to solve the urgent issue of developing stable and efficient blue materials and their devices. [2][3][4][10][11][12][13] While great progress has been made,s ome key challenges remain to be tackled. [2][3][4][10][11][12][13] While great progress has been made,s ome key challenges remain to be tackled.…”

Highly Efficient Bipolar Deep‐Blue Fluorescent Emitters for Solution‐Processed Non‐Doped Organic Light‐Emitting Diodes Based on 9,9‐Dimethyl‐9,10‐dihydroacridine/Phenanthroimadazole Derivatives

“…Recent studies have demonstrated that higher out-coupling effi ciencies can be achieved [ 23,24 ] and in some cases the formation of a cross-section of singlet to triplet excitons may be different from that generally calculated in classical statistics. Therefore, it may have possibly resulted from an improved out-coupling effi ciency or singlet-generation fraction.…”