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Twisted Phenanthro[9,10‐d]imidazole Derivatives as Non‐doped Emitters for Efficient Electroluminescent Devices with Ultra‐Deep Blue Emission and High Exciton Utilization Efficiency
Author(s) -
Kaiyasuan Chokchai,
Chasing Pongsakorn,
Nalaoh Phattananawee,
Wongkaew Praweena,
Sudyoadsuk Taweesak,
Kongpatpanich Kanokwan,
Promarak Vinich
Publication year - 2021
Publication title -
chemistry – an asian journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.18
H-Index - 106
eISSN - 1861-471X
pISSN - 1861-4728
DOI - 10.1002/asia.202100559
Subject(s) - electroluminescence , quantum efficiency , exciton , materials science , imidazole , excited state , doping , density functional theory , oled , optoelectronics , acceptor , fluorene , deep blue , molecule , photochemistry , acridine , chemistry , nanotechnology , atomic physics , computational chemistry , stereochemistry , physics , polymer , organic chemistry , layer (electronics) , quantum mechanics , condensed matter physics , composite material
Herein, two deep‐blue emissive molecules ( SAF‐PI and SAF‐DPI ) are designed and synthesized using spiro[acridine‐9,9’‐fluorene] as a donor (D) substituted with 2‐(3‐methylphenyl)‐1‐phenyl‐phenanthro[9,10‐d]imidazole as an acceptor (A), forming twisted D−A and A−D−A structures, respectively. The photophysical studies and density functional theory (DFT) calculations reveal that both molecules exhibit hybridized local excited and charge transfer (HLCT) characteristics with deep blue emission color. They are effectively applied as non‐doped emitters in OLEDs. Particularly, SAF‐PI ‐based device achieves the high‐definition television (HDTV) standard blue color emission peaked at 428 nm with CIE coordinate of (0.156, 0.053), a narrow full width at half maximum of 55 nm, a maximum external quantum efficiency (EQE max ) of 4.57% and an exciton utilization efficiency of 65%.