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Improved red dopants for organic electroluminescent devices
Author(s) -
Chen C. H.,
Tang C. W.,
Shi J.,
Klubek K. P.
Publication year - 1998
Publication title -
macromolecular symposia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.257
H-Index - 76
eISSN - 1521-3900
pISSN - 1022-1360
DOI - 10.1002/masy.19981250103
Subject(s) - electroluminescence , dopant , fluorescence , materials science , quenching (fluorescence) , photochemistry , doping , photoluminescence , chromaticity , pyran , oled , luminescence , optoelectronics , chemistry , organic chemistry , nanotechnology , optics , physics , layer (electronics)
A t ‐butyl substituted red fluorescent dye, 4‐(dicyanomethylene)‐2‐ t‐butyl ‐6‐(1,1,7,7‐tetramethyljulolidyl‐9‐enyl)‐4 H ‐pyran (DCJTB), has been found to be an excellent dopant in AIQ 3 which produces a highly efficient organic EL device with improved red chromaticity. Unlike 4‐(dicyanomethylene)‐2‐ methyl ‐6‐(1,1,7,7‐tetramethyljulolidyl‐9‐enyl)‐4 H ‐pyran (DCJT), DCJTB can be synthesized in a pure form directly from the unsymmetrical 4‐(dicyanomethylene)‐2‐( t ‐butyl)‐6‐methyl‐4 H ‐pyran without the contamination of the non‐fluorescent bis ‐condensation byproduct which is prevalent in the DCJT preparation. Both photoluminescence and electroluminescence in the solid films of DCJTB in AlQ 3 are modestly enhanced by the extra t‐butyl substitution as a result of a reduction in the effect of concentration quenching. The operation stability of the DCJTB doped EL device is superior, having a half‐life of over 5,000 h driven at an initial brightness > 400 cd/m 2 .