Synthesis and characterization of carbazole dendronized coumarin derivatives as solution-processed non-doped emitters and hole-transporters for electroluminescent devices
Synthesis and characterization of carbazole dendronized coumarin derivatives as solution-processed non-doped emitters and hole-transporters for electroluminescent devices
A series of green-emitting thiophenyl coumarin-cored carbazole dendrimers containing carbazole dendrons up to the third generation as substituent were synthesized and characterization. Their optical, thermal, electrochemical, and electroluminescent properties as non-doped solution-processed light-emitters for OLEDs were investigated. By incorporating carbazole dendrons in the molecule, we are able to reduce the crystallization and retain the high emissive ability of a planar thiophenyl coumarin fluorescent core in the solid state as well as improve the thermal stability of the material. These dendrimers showed a bright-green fluorescence and can form morphologically stable amorphous thin films with glass-transition temperatures as high as 285 degrees C. Simple structured solution-processed OLEDs using these materials as hole-transporting non-doped emitters and BCP as a buffer layer emit a stable green electroluminescence (lambda(EL)=502-526 nm) with high luminance efficiencies (up to 7.92 cd/A at 7.39 mA/cm(2)) and high green color purity (CIE=0.26, 0.62, which are close to the pure green color). (C) 2014 Elsevier Ltd. All rights reserved.
Photodimerization of coumarins in micelles: limitations of alignment effect
作者:K. Muthuramu、N. Ramnath、V. Ramamurthy
DOI:10.1021/jo00159a016
日期:1983.6
Synthesis and characterization of carbazole dendronized coumarin derivatives as solution-processed non-doped emitters and hole-transporters for electroluminescent devices
A series of carbazole dendronized coumarin derivatives (CTmGn, m = 0–2, n = 1–3) containing oligothiophenyl coumarins as cores and carbazole dendrons up to the third generation as substituents were synthesized and characterized. Their optical, thermal, electrochemical, and electroluminescent properties as non-doped solution-processed light-emitters and hole-transporters for OLEDs were investigated. They exhibited a bright light blue to yellow fluorescence with solution fluorescence quantum yields (ΦF) of about 0.10–0.40 and morphologically stable amorphous thin films with glass transition temperatures as high as 285 °C. As emissive layers, solution-processed OLEDs with the structure of ITO/PEDOT:PSS/CTmGn/BCP/LiF:Al emitted light blue to yellow colours with a maximum luminance efficiency as high as 7.92 cd A−1 and a low turn-on voltage of 3.6 V. As hole-transporting layers, solution-processed OLEDs with the structure of ITO/PEDOT:PSS/CGn/Alq3/LiF:Al showed a bright green emission (λEL = 518 nm, CIE = 0.27, 0.53) with a maximum luminance efficiency as high as 6.54 cd A−1 and a low turn-on voltage of 2.5 V.