| Abstract
| - Because polymeric materials have recently found widespread use in light-emitting devices,we decided to exploit a novel group of copolymers as active materials in such devices andmanaged to obtain polymeric electroluminescent diodes emitting blue light. The electroluminescent devices were fabricated using the copolymers composed of 2-(carbazol-9-yl)ethyl methacrylate (CEM) and 3-phenyl-7-methacryloyloxyethoxy-1-methyl-1H-pyrazolo[3,4-b]-quinoline (MEPQ). The concentration of MEPQ in the copolymers was kept at a low leveland changed from 0.5, 1, 2, 5 to 8 mol %. The turn-on voltage for light emission was 8 V. Itwas found that the emission peaks of the electroluminescent devices were blue-shifted by≈9 nm in comparison to photoluminescence spectra of the copolymers in thin film. Moreover,as the concentration of MEPQ in the copolymers was increased from 0.5 to 8 mol %, thephotoluminescence emission peaks shifted slightly to the red from 447 to 455 nm, while theelectroluminescence emission peaks moved from 438 to 447 nm. Because MEPQ groups arebound to the polymer backbone, light emission was equally spread on the whole surface.
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