Synthesis and optoelectronic properties of high transparent polymer based anode materials with good wetting abilities and their application in electroluminescent devices

Abstract

Electroluminescent (EL) phenomenon has been widely used in the illumination industry such as light emitting diode (LED) and organic light emitting diode (OLED) nowadays. In this research, flexible EL devices were fabricated by using the flexible substrates and conductive polymer poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) dispersions as the anode materials. The PEDOT:PSS dispersion was firstly prepared by oxidative polymerization while PSS was served as a polymeric template. Via introducing poly(vinyl pyrrolidone) (PVP) ethanol solution into the PEDOT:PSS dispersion, viscosity and wetting ability of the mixed PEDOT:PSS/PVP solution were enhanced in the same time. The three formed PEDOT:PSS/PVP thin films on glass substrates presented good conductivity and high transmittance (transmittance >76%). The wetting abilities of these PEDOT:PSS/PVP dispersions on the PET films coated with the low dielectric resin were evaluated from the contact angle measurements. It showed that the contact angle was decreased with increasing the addition of PVP ethanol solution. The different PEDOT:PSS/PVP dispersions were further used as the anode material in the EL flat plates and EL wires by dip coating process. Uniform and smooth conductive thin films with high transmittance were formed on the low dielectric resin layer. The luminance of these EL devices was observed and photographed after connecting to 110V AC power.