Decreased degradation of poly(p-phenylene vinylene) films at the indium–tin oxide interface

摘要

This article discusses a strategy to reduce the degradation of a poly(p-phenylene vinylene) (PPV) film at the interface with an indium–tin oxide (ITO) electrode. It consists of using a less aggressive leaving group, the sodium dodecylbenzenesulfonate salt (DBS), in the chemical synthesis of PPV starting with the polymer precursor, and performing the thermal conversion into PPV at a lower temperature (100 °C) than in the conventional synthesis. The absorbance spectrum for an ITO/PPV + DBS film indicated that the polymer is less degraded and has the emission efficiency increased by ca. 4.5 times in comparison to ITO/PPV films obtained with the conventional procedures, i.e., with thermal conversion at 200 °C, in vacuum, during 2 h. The main reason for the enhanced performance of the route reported in this article is a decrease in the oxygen concentration at the ITO/PPV interface, as inferred with X-ray Photoelectron Spectroscopy which corroborates the optical properties.