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Near‐IR Emitting Iridium(III) Complexes with Heteroaromatic β‐Diketonate Ancillary Ligands for Efficient Solution‐Processed OLEDs: Structure–Property Correlations
Author(s) -
Kesarkar Sagar,
Mróz Wojciech,
Penconi Marta,
Pasini Mariacecilia,
Destri Silvia,
Cazzaniga Marco,
Ceresoli Davide,
Mussini Patrizia R.,
Baldoli Clara,
Giovanella Umberto,
Bossi Alberto
Publication year - 2016
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201509798
Subject(s) - iridium , phosphorescence , oled , propane , electrochemistry , luminescence , quantum efficiency , chemistry , photochemistry , quantum yield , materials science , fluorescence , optoelectronics , catalysis , organic chemistry , physics , electrode , layer (electronics) , quantum mechanics
Three NIR‐emitting neutral Ir III complexes [Ir(iqbt) 2 (dpm)] ( 1 ), [Ir(iqbt) 2 (tta)] ( 2 ), and [Ir(iqbt) 2 (dtdk)] ( 3 ) based on the 1‐(benzo[b]thiophen‐2‐yl)‐isoquinolinate (iqtb) were synthesized and characterized (dpm=2,2,6,6‐tetramethyl‐3,5‐heptanedionate; tta=2‐thienoyltrifluoroacetonate; dtdk=1,3‐di(thiophen‐2‐yl)propane‐1,3‐dionate). The compounds emit between λ =680 and 850 nm with high luminescence quantum yields (up to 16 %). By combining electrochemistry, photophysical measurements, and computational modelling, the relationship between the structure, energy levels, and properties were investigated. NIR‐emitting, solution‐processed phosphorescent organic light‐emitting devices (PHOLEDs) were fabricated using the complexes. The devices show remarkable external quantum efficiencies (above 3 % with 1 ) with negligible efficiency roll‐off values, exceeding the highest reported values for solution‐processible NIR emitters.