Premium
Synthesis of a green‐emitting alternating block copolymer
Author(s) -
Gurge Ronald M.,
Hickl Markus,
Krause Gernot,
Lahti Paul M.,
Hu Bin,
Yang Zhou,
Karasz Frank E.
Publication year - 1998
Publication title -
polymers for advanced technologies
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.61
H-Index - 90
eISSN - 1099-1581
pISSN - 1042-7147
DOI - 10.1002/(sici)1099-1581(199808)9:8<504::aid-pat806>3.0.co;2-y
Subject(s) - materials science , wittig reaction , phenylene , electroluminescence , copolymer , differential scanning calorimetry , indium tin oxide , light emitting diode , polymerization , polymer chemistry , photochemistry , layer (electronics) , optoelectronics , organic chemistry , polymer , chemistry , composite material , physics , thermodynamics
An alternating block copolymer, poly(1,8‐octanedioxy‐2,6‐dimethoxy‐1,4‐phenylene‐1,2‐ethenylene‐1,4‐phenylene‐1,2‐ethenylene‐1,4‐phenylene‐1,2‐ethenylene‐3,5‐dimethoxy‐1,4‐phenylene), 1 , was synthesized, and characterized using Fourier transform infrared spectroscopy, nuclear magnetic resonance, gel permeation chromatography differential scanning calorimetry ultraviolet and elemental analysis. Light‐emitting single‐layer test diodes using this soluble, processible copolymer as the active layer (i.e. indium tin oxide/ 1 /Ca,Al) emit green light with a luminescent spectral maximum at 513 nm. The single‐layer device had a brightness of about 80 cd/m 2 at a current density of 100 mA/cm 2 with an internal quantum efficiency of 0.3% photon/electron. Optimization of the light‐emitting properties of 1 was achieved through variation of a key Wittig polymerization step in the synthesis, using trialkyl rather than triaryl phosphonium salts in an appropriate solvent mixture to achieve nearly regiospecific trans‐olefination. This provided an improvement over earlier procedures, which require a post‐Wittig isomerization to minimize the presence of electroluminescence‐inhibiting cis‐bonds. © 1998 John Wiley & Sons, Ltd.