Visible-light electroluminescent diodes using poly(arylene vinylene)

Summary form only given. The processability of conducting polymers has been well studied and significantly progressed. Among various conducting polymers, poly(arylene vinylene) such as poly( p-phenylene vinylene), PPV and PNV, have attracted much interest as materials for use in nonlinear optics as well as highly conductive polymers, since they can be obtained as tough, flexible and dense films, and show superior chemical stability against moisture and oxygen at room temperature. Recently, we reported fundamental physical properties of PNV during electrochemical doping and proposed various types of applications, such as rechargeable batteries, optical recording, and Schottky-gated field-effect transistors, utilizing PNV film. However, realization of a visible light-emitting diode using PNV has yet to be reported. This is the first article concerned with the fabrication and the fundamental properties of a PNV EL diode. That is, an orange electroluminescent (EL) diode utilizing PNV has been demonstrated for the first time and the EL properties of PNV are discussed in comparison with those of EL diode utilizing PPV. The EL emission of these two devices can be interpreted in terms of radiative polaron exciton formed by the injection of electrons and holes. Although the EL intensity of the PNV light-emitting diode is weak compared to that of the PPV diode, orange emission was clearly observed under normal room light even at low driving voltage. These results are discussed in terms of the difference in effective conjugation length mind the interchain transfer of polaron excitons generated by the injection of electrons and holes.