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Efficient Vacuum‐Processed Light‐Emitting Diodes Based on Carbene–Metal–Amides
Author(s) -
Conaghan Patrick J.,
Menke S. Matthew,
Romanov Alexander S.,
Jones Saul T. E.,
Pearson Andrew J.,
Evans Emrys W.,
Bochmann Manfred,
Greenham Neil C.,
Credgington Dan
Publication year - 2018
Publication title -
advanced materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 10.707
H-Index - 527
eISSN - 1521-4095
pISSN - 0935-9648
DOI - 10.1002/adma.201802285
Subject(s) - electroluminescence , materials science , quantum efficiency , dopant , oled , carbene , optoelectronics , luminescence , diode , doping , layer (electronics) , light emitting diode , metal , amide , nanotechnology , organic chemistry , chemistry , catalysis , metallurgy
Efficient vacuum‐processed organic light‐emitting diodes are fabricated using a carbene–metal–amide material, CMA1. An electroluminescence (EL) external quantum efficiency of 23% is achieved in a host‐free emissive layer comprising pure CMA1. Furthermore external quantum efficiencies of up to 26.9% are achieved in host–guest emissive layers. EL spectra are found to depend on both the emissive‐layer doping concentration and the choice of host material, enabling tuning of emission color from mid‐green (Commission Internationale de l'Éclairage 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%) while maintaining a short radiative lifetime of triplets (<1 μs).