Electroluminescence blue, green

T. Ahn, S. Song, and H. Shim, Highly photoluminescent and blue-green electroluminescent polymers new silyl- and alkoxy-substituted poly(p-phenylene vinylene) related copolymers containing carbazole or fluorene groups, Macromolecules, 33 6764-6771, 2000. 

K. Tada, M. Onoda, M. Hirohata, T. Kawai, and K. Yoshino, Blue-green electroluminescence in copolymer based on poly(l,4-phenylene ethynylene), Jpn. J. Appl. Chem., 35 L251-L253,... 

It is well known that solid-state LECs exhibit a significant response time since electroluminescence can only occur after the ionic double-layers have been built up at the electrode interfaces [79,82]. Since in this case only the PFg anion is mobile, the double-layers are formed by accumulation and depletion of PFg at the anode and cathode, respectively. The LEC device with 45 started to emit blue-green light at a bias of 5 V after several minutes. The electroluminescence spectrum, as shown in Fig. 36 (trace a), is very similar to the photoluminescence spectrum recorded for a spin-coated film on glass and of a solution of the complex. For comparison, the electroluminescence... 

H. W. Heuer and R. Wehrmann, Five-Coordinate of Gallium(III) Carboxylate Complexes With Blue/Blue-Green Photo- and Electroluminescence, Procedures for their Production as Well as their Use, DE 10225826, 2003. 

Hu B., F Karasz.E., Blue, green, red, and white electroluminescence from multichromophore polymer blends, /, Appl. Phys. 93, (November 2003)1995, doi 10.1063/ 1.1536018... 

Fig. 2.34 Electroluminescence from a 50 50 by weight PFB F8BT blend spun from xylene solution. Applied voltages were 1.87, 1.9, 1.95, 2.5, and 3.0 V for the cyan, blue, green, red, and black graph, respectively. Typical l-V-values, measured from a different but similar device, are plotted in the inset.

Liu, J., Zhou, Q., Cheng, Y., Ceng, Y, Wang, L., Ma, D., Jing, X., Wang, E, 2005. The first single polymer with simultaneous blue, green, and red emission for white electroluminescence. Adv. Mater. 17, 2974-2978. 

Another fluorene copolymer containing the luminescent dye [4-dicyanomethylene-2-methyl-6-4//-pyran (DCM) as acceptor compound was irradiatiated with UV light in the presence of gaseous triaUcylsilanes. This reagent selectively saturates the C = C bonds in the DCM comonomer units while leaving the fluorene units essentially unaffected. As a result of the photochemical process, the red electroluminescence of the acceptor compound vanishes, and the blue-green electroluminescence from the polyfluorene units is recovered. Compared with previous processes based on polymer blends, this copolymer approach avoids problems associated with phase-separation phenomena in the active layer of OLEDs [256]. 

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