AC properties of polyphenylene-vinylene thin films

Summary form only given. We investigate the electrical properties of these films for a general research program aiming to fabricate elctronic devices based on PPV polymer. Previous study on the conductivity on metal-PPV-metal devices has shown the key role of the interfacial layer between the polymer and the metal on the conduction mechanism. In this work, the frequency and temperature dependence of the complex conductivity was measured in similar devices. From the data analysis, it has been shown that two relaxation mechanisms could be distinguished. The high frequency regime is related to bulk mechanism involving charge carrier detrapping with an activation energy of ~ 0.4 eV. The low frequency mechanism is found to be strongly dependent on the temperature and is supposed to be originated from the interface polymer-metal. These results are in good agreement with those obtained in DC study showing the important influence of the contact in the charge transport in these devices.