1. Efficient Vacuum-Processed Light-Emitting Diodes Based on Carbene-Metal-Amides
- Author
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Andrew J. Pearson, Manfred Bochmann, Emrys W. Evans, S. Matthew Menke, Saul T. E. Jones, Dan Credgington, Alexander S. Romanov, Patrick J. Conaghan, Neil C. Greenham, Menke, S Matthew [0000-0003-4468-0223], Romanov, Alexander S [0000-0003-2617-6402], Jones, Saul TE [0000-0001-6007-2530], Pearson, Andrew J [0000-0003-3634-4748], Bochmann, Manfred [0000-0001-7736-5428], Greenham, Neil C [0000-0002-2155-2432], Credgington, Dan [0000-0003-4246-2118], and Apollo - University of Cambridge Repository
- Subjects
thermally activated delayed fluorescence ,Materials science ,02 engineering and technology ,Electroluminescence ,010402 general chemistry ,01 natural sciences ,7. Clean energy ,law.invention ,law ,OLED ,General Materials Science ,Diode ,carbene-metal-amide ,Dopant ,business.industry ,host-free ,Mechanical Engineering ,Doping ,vacuum-processed ,organic light-emitting diodes ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,Mechanics of Materials ,Optoelectronics ,Quantum efficiency ,0210 nano-technology ,Luminescence ,business ,Light-emitting diode - Abstract
Efficient vacuum-processed organic light-emitting diodes (OLEDs) have been fabricated using the carbene-metal-amide material CMA1. Electroluminescence external quantum efficiencies of greater than 24 % have been achieved with host-guest emissive layers utilizing a 1,3-bis(N-carbazolyl)benzene (mCP) host as well as in host-free emissive layers comprising pure CMA1. Furthermore, an external quantum efficiency greater than 26 % has been achieved by substitution of the emissive layer host for a symmetrical, non-polar variant. Electroluminescence spectra are found to depend on both emissive layer doping concentration and the choice of host material, enabling tuning of emission colour from mid-green (Commission Internationale de l’Eclairage co-ordinates [0.24, 0.46]) to sky blue ([0.22 0.35]) without changing dopant. This tuning is achieved without compromising luminescence efficiency (> 80 %) and maintaining a short radiative lifetime of triplets (< 1 µs).
- Published
- 2018
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