| 초록 |
To improve efficiency of polymer light-emitting diodes (PLED), balance of charge injection and transport from each electrode is important. For charge balance, multilayer architecture is required. In case of a PLED, [poly-(3,4-ethylenedioxythiophene)] (PEDOT) doped with [poly(styrenesulfonate)] (PSS) were developed and optimized for hole injection layer(HIL). Introduction of PEDOT:PSS often improves the lifetime and also luminous efficiency. However interface of ITO/PEDOT:PSS is not stable in the PLED. When PEDOT:PSS is coated onto Indium-tin-oxide (ITO), ITO could be etched by sulfonic acid and some indium could be diffused into PEDOT:PSS. HIL requires good solvent resistance and thermal and electrochemical stability. In addition the highest occupied molecular orbital (HOMO) of the HIL has to be close to, or even below, the HOMO of the emitting polymer. We synthesized new hole injection materials that combine perfluorocyclobutane groups with hole injection unit. The monomer was coated directly onto the ITO and in situ thermally polymerized under nitrogen. The polymers were characterized by NMR, FT-IR, and GPC. Thermal, optical, and electrochemical properties were also investigated. |
