| 초록 |
Polymer blending is well known as a convenient and efficient way to improve electro-optic properties of polymer light emitting diode (PLED). More importantly the control of the microstructure of the mixed polymer is one of the most critical factors to determine the final properties of PLED devices. Thin films of a poly(2-methoxy-5-(2’-ethylhexyloxy)-p-phenylenevinylene)(MEH-PPV) and poly(methyl methacrylate) (PMMA) blend, fabricated by spin coating, has been known to improve efficiency of a device due to both the hole-trapping ability of PMMA domains and the effective hole-electron recombination at the domain interfaces. We introduce a new and robust method, corona discharge coating (CDC), to further enhance interfacial area. Our method is based on using corona discharge generated between a sharp metallic needle and a plate bottom electrode under high electric filed. The uniformity of the thin film by CDC depends on various factors including electrical field, polarity of solvent and polymers. We obtained that the domain size of minor phase significantly reduced using CDC. Well defined spherical PMMA nanostructure with approximately 50nm in size diameter was generated in a MEH-PPV/PMMA(75/25) blend. Highly increased interfacial area in the blend guarantees improved device performance. We have investigated the relation ship between microstructure obtained by CDC and electro-optic properties. |
